Audacity

I'm hoping to find some help find out which skills I need to look into.
I play Dungeons and Dragons via online table top and like to, to the best of my ability, add audio flourishes and battle music. Occasionally, I'll find a song that has a specific segment that would be really good as a battle music or will capture the energy I'm going for. The problem I'll often run into is the segment I want doesn't cleanly loop if I cut the song and play it on repeat.
Can anyone direct me to what specific skills/tools I need to learn to clean up and loop specific segments of a song? Please keep in mind that I have zero training as a musician and audio engineer, so absolute baby stuff is appreciated.