Couple things:

1.) how dark is the yellow? 2.) what color are you changing to? 3.) get off TikTok 😂

If the existing color isn’t too dark you may get away with a coat or two of a high-solid content paint, depending on the new color. I would recommend using a primer anyway though.

When it comes to the actual act of painting, you’ve probably seen best practices on that in your research. A good rule of thumb is to zig-zag to cover, then back roll for uniformity. The most important thing is to make sure the last stroke of the roller/brush be in the same direction across the room