Its your freestyle. It’s not like you’re going to copy another person’s freestyle from a person who used that song anyway.
If you want some song recommendations.
Hamilton — You Had It (Listened to this alot before, apparently Takeshi Matsuura used it too in his 2014 Japan Nats freestyle)
Otherside (Remix) — Macklemore and Ryan Lewis Ft. Fences (You might have to edit out the rap part if you’re competing)
Stronger — Kanye West (ALWAYS A GOOD SONG TO YOYO TO)
Power (Trap Remix) — Kanye West (Pretty good to yoyo to, Used in the video: Samm Scott - Moment)
Everybody Wants to Rule the World — Lorde (Not gonna lie, it’s a goto song of mine because it was in the Assassin’s Creed Unity trailer haha, also it’s about 2:30 long so you’ll have to edit in a song or edit out a part of the song if competing in a 3 min or 2 min freestyle respectively)
Use stuff like remixes or something since some people might just use the normal version of the song that people could have heard tens of hundreds of times.