is there a way to ensure that you are not infringing someones property besides talking with a lawyer and paying 200$ for that?
Yeah - it's called "market research". That's all you're paying a lawyer to do.
Its really pretty simple.
Don't use copyrighted material in your games. Vet everything you don't create yourself to make sure its not somebody else's.
Come up with new and unique trade names for your products - ones that don't have "prior use" in any similar industry that could cause confusion. Come up with a name, then do a google search, if it doesn't exist on google, you're probably safe.
In the USA, until you get to AA or AAA size, that's sufficient for a start. You can register trademarks as additional evidence of "prior use" if you get sued. and a copyright is created as soon as you save a text file. its on your hard drive - you're the author - and it has a date. helps if you put a copyright statement in the doc itself too.
use "Copyright <some year> <your name or your trade name> All rights reserved" on everything.
use "TM" or "Reg TM" (if registered trademark) for your trade names, logos, etc.
and then get back to coding and stop worrying about it. we should all hope to be so successful as to actually have to really worry about such things.
of course, the laws vary by country. you mileage may vary.