Should I do free shipping on bundles or no?

I’m fairly new to selling on depop, so I still haven’t quite figured everything out yet. I got a message from somebody today asking if I do free shipping on bundles. Now, I’ve seen people who have done free shipping on bundles actually lose money because of the high cost of it. Also, I don’t even know how to bundle items. So, what do I tell them? Do I do free shipping or not? And, how do I even bundle items? Please help lol