When you want to cheerfully accept someone's request, you can say "I'd be glad to."

You can also follow "I'd be glad to" with a phrase describing the action that you'd be glad to do. For example, you can say:

I'd be glad to help you with that.

I'd be glad to teach you how to do it, if you're interested.

This is a good way to volunteer to do something. It sounds friendly and helpful.