Questions about music producing and uploading to Soundcloud.

I want to possibly publish beats or songs in the future and I just have a few concerns regarding legal aspects of the field.

​

What's stopping other people from stealing one of my songs and claiming it as their own? How can one prove that they created the beat with unrefutable evidence?

​

Can't someone under a company simply claim the song as their own and keep the rights since they have more monetary backing?