Great question! I did a post on a DIY Starter Kit a year or so ago with a list of essentials that I like to have on hand to tackle a variety of projects! So check that out to get some ideas for what to add to your kit along with the stuff you listed above.
As for a drippy glue gun, you can see if there’s an option to use it on Low or High setting because sometimes the high setting heats it up so hot it gets drippy. If not, I usually just use a scrap of cardboard to rest the glue gun on flat so it protects the surface I’m working on from glue and heat. You can also use an old piece of tile!