Don't get freaked out!! I am currently learning how to live with my new permanent ileostomy (after having a loop ileo for more than 6 years) and it is no big deal. This time around mine is a much different shape so my products have changed and your ET nurse will set you up with the products you need FOR YOU. Everyone is a little different with products, but one that I would STRONGLY suggest is to try the Eakin brand seals. They are much better than paste (and does the same thing) and makes fitting to certain flanges a piece of cake! Not everyone has to cut their wafer to size, it will just depend on YOUR stoma, as well as how long you can go between changes. The climate where you live as well as how active you are will play a part as to how often you'll need to change your appliance. You can change it 1-2 times a week in the beginning and figure out how well yours last and maybe go once a week. Many people on this forum are lucky enough to do once a week and during the cooler months, I go 5 days, but in the warmer months, when I am outside and really active, I have had to change every 3 days.
Like with anything in life, there are learning curves, but I think that is the hardest thing when learning to deal with an ileo. You can't let any of it get you worried...for me it was the BEST thing I ever did. I got my life back, not only for me, but for my husband and daughter! I wish I had done it sooner