I have a Youtube Channel where I post mostly speedpaints. I use a lot of instrumental/orchestral versions of songs made by the youtuber Koala Pop who allows use with credit (I originally credited in the description but now do it in the video itself with onscreen text). I personnally prefer with music because it helps with the performance element of it, plus my speedpaints are all over 4 mins, some nearly 30mins, so that long in complete silence would be weird.
As others have said you can also use youtube and instagram's free to use library for reels/shorts (these have copyrighted music in them) or other free to use and copyright free upon credit music platforms. I personnally don't bother if any of the music I use gets flagged by the system because I'm basically never going to get money on youtube and most music copyright flags never affect the channel, they don't ban you for using music they just stop monetization for that video and add extra credit box over the description with a link to the music, which I'm actually glad for it means people are more likely to go and listen to music I like. If you have less than 900 subs and 7000 hours of watchtime, that's not happening any time soon.
You can check some of my speedpaints out here: