Don’t spend money on your pet. It is an awesome long-term F2P goal to have, and it is cool to see that gradual progression. I have put a fair amount of money into the game at this point, and all of it has gone into vault and character slots (with a couple random mystery box rolls thrown in…don’t do that lol). I highly recommend you do the same. It is fantastic to be able to store so much in the vault, and great to be able to have a living character of every class plus a few spare slots.
imo, once potion rack is maxed, go for character slots until you have 18 total (one of each class, and one extra of your favorite), then everything else goes into vault slots. That’s a whole lot of discord competitions you have to win, but it is something to work toward ;).