PV&PL

You Tube is just a platform, depends on what you are watching, I have seen some weird stuff there but have no doubt that there must be videos from people who do know what they are doing.
 
But how do you know if you do not know?

First, I would drop that lawyer.
 
Second, you collected evidence that is not needed.  Birth certificate, passport and police report of the beneficiary is not needed until the interview stage, and even then it is what your fiance will bring with him and has no use in your hands.  Infact, the police clearance certificate might be expired by the time your fiance needs to use it.
 
For difficult countries, people frontload relationship evidence, like boarding passes and photos of time spent together.  The only required submittals for the I-129F are proof that the petitioner is a USC, signed letters of intent to marry, and proof that you met in person within the last 2 years.  Other things that may be needed is any divorce certificates (if applicable), proof that website/agency follows marriage broker regulations (if you met through a marriage broker), and court documents regarding crimes (if applicable).
 

I think it's fine to do business with family if they are competent, but if they are doing it for you at a discounted rate you might also be getting discounted effort. 
 
As for losing the money you already paid him, think about it this way. Imagine it's 18 months from now and you still haven't gotten your NOA2 because of incompetence, how much would you pay to have it in your hands? Dropping that lawyer now and taking the $500 loss might end up saving you 6 months of waiting on the back end of this process.
 
If you want to use an attorney (we are using one), then make sure you have complete confidence in them, research them. 

To answer your question, yes, you should drop him. From what you’re telling he is advising you regarding the process - it is false. $500 is not that bad of a loss considering he probably would have cost you much more down the line, including delays and a whole lot of stress.

Vast majority of us here have filled out the forms on our own. If you feel like you need help and can’t do it on your own, you should do research and look for recommendations regarding attorneys. VJ has some partners here, also you can look for them in aila.org.
 
Also, a strong word of advice, please do not rely on YouTube videos….. we have seen so much false information coming from there.

I would drop him like a hot potato.  He sounds unorganized, unprofessional, and lacking in very basic immigration process  knowledge.  Why throw more money down the drain?