Good Morning! My first post/question as a new CVHS member! 
I would like recommendations as to where to purchase a Gala apple tree as well as a plum tree (I am not sure what kind of plum I would like…maybe a couple varieties lol!).
Thank you in advance!
Welcome Adena!
here are several nursery’s around town that may be able to help you, try Outback Nursery http://outbacknursery.ca and Art Knapps https://artknappcourtenay.ca. The address of each is on their web sites. Though they may be sold out of varieties you are looking for.
There are several nursery’s in Campbell River as well: Sticks and Stones https://www.mapquest.com/canada/british-columbia/sticks-n-stones-nursery-25836478?s1recircid=AVsuwie90nCBjEVhNLdM and Campbell River Garden Centre https://crgardencentre.com. Both have good selection of plants.
You will need several plum trees to pollinate each other. The Nursery should be able to help you with that. Likely the same applies to apple trees too.
If you do not find what you are looking for now, it might be best to wait until next year, or look further a field. There are good nursery’s in Duncan (Ditner’s) and several on the Saanich Peninsula near Victoria.
Good luck with the trees!
Gordon Stewart