These are my personal opinions:
The best way to learn the proper pronunciation is to get feedback from a native speaker of hindi who also has knowledge of Sanskrit and AND MOST IMPORTANTLY phonetics. Also you too must be acquainted with knowledge of phonetics.
There are many things that you would never be able to figure out on your own. You need somebody's help. There is no other way. Professor Alexander arguelles did a 4 part video series on YouTube named accent formation in foreign language learning. I suggest you to take a look at it. Most of the comments on his german vidoes agree that His german accent is very good. He credits that to his one on one private sessions with a native german phonetician. Its not that hard. You would get it. Dont worry.
Personally I can help you if you want.
Apart from pronunciation you need grammer to learn sanskrit. I suggest you to first build up your vocabulary and than after accumulating a lot of words, you should go for grammer. It has been my experience that grammer rules make much more sense after you've become familiar with the language.
Just as If you go to a new city and somebody gives you directions they won't make much sense to you because the city is unknown to you and you are not aware of the landmarks.
While if you have spent some time in the City and you are aware of the landmarks than those same instruction would make much more sense to you. Because now you are aware of the city.
If you trying to learn math and you go for calculus and most advanced math there is and try to learn that first before you've learnt the most basic form of addition and subtraction and multiplication, you would find it exceptionally hard. That why I suggest you to build up your vocabulary first and then go for grammar. At some point you Have to learn grammer. There is no way around it. But first learn vocabulary and get yourself familiar with the language.
With That being said, you still need rudimentary knowledge of basic grammar for instance what is a noun, what is a verb, what is a pronoun. Also you need rudimentary knowledge of the grammer of case based indo European langauges. What is a case and how they work in contaxt of Indo European languages, What is a nominative case what is accusative case. I suggest you to momorize declarations tables of nominal inflection of अ stem masculine, आ stem femenine and a अ stem neuter nouns. And a complete verb conjugation table of a first gana parasmeipadi root.
Also you need to take a look at sanskrit grammer book from time to time, just to be away of such and such rules exist, otherwise you wont be able to notice them on your own.
Dont try to nail down or memorize grammar rules at this early stage.
The best way to learn vocabulary is to read long text with word by word translation
I suggest you to use valmiki ramayana iit kanpur.
There you can find valmiki ramayana with english translation, along with orignal text with sandhi and word by word translation without sandhi. Unfortunately it doenst have last kanda. Verse by verse First read English translation and than its word by word non sandhi translation. Leave orignal at this stage. After you've read all the ramayana which is available there, you would be able to make sense of the original text with the help of word by word translation and without pure english translation.
Dont worry about forgetting vocabulary. Its part of learning. You have to keep on forgetting and relearning it in order for it to become fossilised.
There is a thing called Spaced repetition
The basis for spaced repetition research was laid by Hermann Ebbinghaus, who suggested that information loss over time follows a Forgetting curve, but that forgetting could be reset with repetition based on active recall. You can read about it here https://en.m.wikipedia.org/wiki/Forgetting_curve
It basically suggests that you need to keep coming across same thing again and again in order to put that thing in your long term memory
and reading is the best way to do it.
For you will come across the same vocabulary again and again
Language learning by reading is kind of like a Galton Board. Every time you see a word, your understanding of that word is slightly increased. After some time you understand words in the language based on how frequent they are. This is automatic. Sometimes you may feel like you don't make any progress, but you have some understanding of a lot of words at the same time. There are thousands of words ready to be "activated", which they will be by reading them a few more times. They are just waiting to reach the line which is needed to be able to use that word in a sentence. And when those words reaches the line, it will open a new world of words because all words in a language are connected.
One more thing.
Some people make lists of the words that they want to memorize.
This type of words list is not a good way to memorize words.
Because you need context in order to stuck the word to your long term memory.
For exemplar you want to memorize the word "verbatim" the word would not stuck to your long term memory
If you just write the isolated word "verbatim" in a list
You need this word "verbatim" in a Sentence
Like this Some passages in the book are taken "verbatim" from the blog
And you need many example of this one word "verbatim" in various different context just to put this one word in your memory.
Thats why the most convenient way is to just keep on reading
Everything else would takecare of itself.
One very important advice is to listing to the same thing that you read.
That's because your brain process Information better when we feed the brain the EXACT SAME INFORMATION in different ways.
So use various ways.
First read the text.
Than listen to the same text without reading.
Than read and listen at the same time.
Also Please search about comprehensive input hypothesis of steven krason.
Its a revolutionary method of learning any languages.
It says that if you read something of which you only understand 90% to 95% you still would be able to accumulate a lot of grammer patterns and vocabulary just by doing gusse work and coming across them regularly
for example if you want to learn sanskrit, just get a text of which you understand around 80% and read it
Do a lot of reading.
Dont look up the meaning of every word.
Try to gusse them.
Just keep reading.
Read 20-40 pages daily and eventually you will learn the language.
The real problem is to get to that 90% because when we start in a languages, we dont even understand 1%.
Thats why you need long texts with word by word transitions. Like that iit kanpur ramayana. That will get you to 70% - 80%.
You have to read it many times. You wont undertand anything in first go.