Hi mybabapeas
YES! Definitely buy your new kitty a cat tree...the taller the better! We have a couple of trees around the house and all our Bengals love them.
As for the food...We feed a mix of wet & dry. We use Royal Canin dry which is left out all day and then we feed each cat 1x pouch of wet (whiskers/Felix etc) twice a day. You will know if the food is upsetting her by the messages she leave you in the litter tray
Personally I've never had a problem with RC. Keep her on the kitten 34 until she is 12 months as it's a good quality food then switch her to one of the adult biscuits. However, spayed cats do put on weight easier so if you think she is getting a little over weight, talk to your vet about switching foods. I know that Royal Canin do a special low-fat biscuit and I know a few people who have switched to this once their cats have been spayed.
Congratulations for choosing to adopt a Bengal...You certainly won’t regret it