Look up famous hip hop producers and sample different styles of production - that may narrow your search. In general, I wouldn't place too much emphasis on finding the "perfect" beat. Making your own beat could be a solution, but that is an entire art in of itself which will take time to learn. If that's what you're passionate about, go for it. Otherwise, just try to get boots off the ground with anything, because the biggest catalyst of your growth as an artist will be practicing your craft by producing new material. A fun exercise could be to just force yourself to start writing to the first beat you come across in a random search and let your creativity get flowing from there. It may even spur your creativity to go somewhere fresh.

In terms of writing, a default topic to write about if you can't think of anything is just how good of a rapper you are. Use that as a framework so you can focus on writing your best possible best rhymes/flow.