itch.io

Nope, Its 100% free and the only times you have to spend money is if you need to buy custom assets from someone else (But u can probably find some for free anyways) and if you need to switch the software to dark mode then you need to pay some money then as well (I hate Light mode), and if you need to get rid of the watermark that appears at the start of your unity game. But Yeah other than these 3 small things its totally free and pretty easy to get used to and its one of the best and most Friendly Free 3D engines out there if you want to make actually good 3D games (Godot is more for 2D and their 3D is really bad in my opinion)

Hope this helps :D