What do I need to know about copyright?

[Morpethian]

A year or two back, someone suggested that I upload videos to YouTube of me singing, and said that I could make money from advertising.  More recently I have thought about putting a group together to play some local venues.
My bugbear is copyright law.  I imagine that most people who upload cover videos to YouTube do not seek copyright permission, but a few do.  Also, I imagine that buskers do not normally seek copyright permission, but maybe some of them do.
Sometimes there are ways around copyright law.  For example I once watched a school production of High School Musical, where I was invited to pay £2 for my ticket, but had the option of a free ticket.  Apparently this was done to avoid paying a copyright fee.
What I wonder is whether or not I should seek copyright permission to perform songs in a small venue such as a pub, where the audience does not pay an admission fee.
Can anyone advise?

[Jerome]

I am no expert on copyright but I have read quite a bit about it. As far as playing in pubs is concerned you won't have any issue because no-one is going to go the expense of chasing a musician over a few tracks in a pub. If however that goes up on YT or some other platform then you have a whole different set of problems. There is no 'one size fits all' in the world of copyright. It's a minefield, and depending on who wrote/performed the track, can become quite complex. The easy answer, from a legal point of view, is perform your own material.

[Morpethian]

Thanks.

My current plan is to seek copyright permission only when I stand to make money from something.