Looking for a lot of Chess Data

Hi everyone. I'm looking to obtain a large dataset of chess games played and the number of moves it took to reach a conclusion (whether it be checkmate or resign or draw). Essentially, I'm looking for count data to analyze and for each game, I'd like to have the ELO/Average Elo of the players involved. 

That's great. Just help yourself to the API data. Plenty available.

Do you know which specific endpoint I should be looking at? I've been looking at the "Games, general. Specific endpoints:" but that requires me to input a certain username

I looked into a similar problem recently and I believe the lichess downloads are what you are looking for, as mentioned by @theturtlemoves. I think that would fit what you are doing better than any of the alternatives (at least as of the last time I checked things out).