Android game google ads, asset usage

Hello dear community members,

This is my first post and the first question on this forum, if i have mistakenly created my topic in the wrong category, i would be very grateful to admins if they would move it.
I have a few questions about creating an Android game and Royalties Payment, i couldn’t find enough information on that matter in the documentation.

My Idea is to create a really simple and minimalistic game on Android, but it will involve having a Humanoid type main character.
I have seen, that UE4 has already a standard biped character model with skeleton and animations, so my question is: Can i use the skeleton and animations that are already built in UE4 and just build my own character model over it and then sell the game? (the game actually is going to be free, but will have ads, there will be a paid version with no ads, on Google Play). I am going to use Google Ads in that game and i would like to know how should i licence the game and how do i have to pay royaltires to Epic Games (as far as i know, royalties start if i’ll earn more than 3000$ on this game, if i am not wrong).

Thank you all in advance,