I got burned by an altcoin, and am trying to learn to use lightning wallet. Can anyone offer some advice?

Hi all,

Well, after years of gains and research, I think I finally understand why Bitcoin is the only avenue. I've just been burned by some altcoins - things I wouldn't particularly consider degenerate stuff - but still got rekt nonetheless. Most of my other research, metrics and diligence seemed to prove pointless in the crypto space.

Most commenters in the sub seem to suggest Munn as the best source for the lightning wallet. But, like...

What do I do now? What are the biggest advantages of lightning?

Should I link it to my existing to bitcoin wallet, or create a new one?

What is the purpose of the lightning wallet?

What's the best ways to top up? Just buy on exchange and send direct the address like normal?

EDIT: Why does it say the invoice expires? Does that mean my address changes too?