What are some alternatives, if I can't get the license for a song I want to use in my 3D short?

The 3D animated short will be less than 10 minutes. I wanted to use about 15 seconds of a 20 year old song, that’s owned by Universal Music, during the ending credits.

I’m not planning to submit it to any festivals or make any money from it. It’s a personal project done with zero budget, only my time.

Does anyone have any experience with music licensing? And know if they’ll ask for a ton of money from a starving artist?

Should I “track down” the actual signer/song writer in the least creepy way possible, and show him the short on a laptop and get the ok from him? or will that not even matter since he doesn’t really own the rights to it.

How about if I hire someone to do a cover of the song, will this be legal? How are artists able to do covers and sell it?

Thank you so much for your time.