I have a friend with Celiac and belong to an online support group ... This is a good link to a site with awesome snack recipes if you are into making your own, and some really helpful lists of safe foods and foods that have hidden gluten:
http://janiceameesglutenfree.com/what-can-i-eat-and-what-do-i-avoid/
being a Celiac myself, the best bet for snacks that don't involve hours of trying and failing with recipes or getting sick from things that say they're gluten free and aren't would be to stick with plain fruits and vegetables. it sucks, but it's better than getting sick or eating homemade gluten free pastries that are harder than concrete and taste like cardboard. (there are some good recipes out there, but they're so hard to find)
Idk where you live but here in the uk most supermarkets have a "free from" section and they have lots of regular snacks like biscuits and stuff that are gluten free. If you have a supermarket with a free from section it's easy because you don't have to spend ages making your own snacks and things, it's also good if you're looking for some kind of junk snack food rather than fruit and things, but fruit is always good too. one of my favorite snacks is hummus and carrots or peppers, hummus is usually gluten free. Here is a list of gluten free snack ideas that might be useful.
i have celiac as well, it's annoying but once you find the good stuff it's not quite as bad. most chips & popcorn are gluten free, but check the ingredients just to be sure (like barbecue chips for example are not) if you're looking for snack stuff like that. regular fruit/dried fruit are always a safe option, as well as veggies, but i'd take fruit over vegetables any day. besides that, my favorite non-meal food things are gluten free rice cakes like these w/ peanut butter, coconut chips if you like coconut, these things called almond pops that taste like blueberry muffins, and energy/granola bars. i eat a lot of salads too, but i guess that counts as a meal.
good luck with this diet change, as i said, it's a pain, but it's really not so bad once you adjust. <3
Just live off of those gluten free juice boxes lmao