There are no silly questions. Barrier cream is always a good thing to have on hand. I still occasionally get butt burn and I'm over 8 years out from surgery. Since you are still early in your takedown, most surgeons would recommend that you use barrier cream on a regular basis, at least for the first few months. So definitely, go ahead and use it, whether you are trying a new food or not.
If you are particularly worried about trying a food with your pouch for the first time, for peace of mind you may want to try the food while you are at home, or a least in an environment where you know you will have easy access to a washroom. Translation: don't eat a burrito and then take a 2 hour car trip. That probably wouldn't be considered a good choice.