this is my first time trying to develop a game with no prior experience in this field. what im asking is: if i make no money from this product then i owe no money to epic games?
UE4 is free to use, with a 5% royalty on gross product revenue after the first $3,000 per game per calendar quarter from commercial products. Read the EULA FAQ for more details.
Information on the EULA can be found here (Frequently Asked Questions - Unreal Engine) and also here (Release and Royalty Tracking Guidelines - Unreal Engine)
You should always read EULA’s before doing anything commercially regardless of company just to C.Y.A. But you are correct that if you make no money, you owe no money. Keep in mind that if you make an app for a mobile device or otherwise and generate revenue from advertisements in the game, you are required to pay money. It’s ** any ** money generated from use of their products.