Food: It is really expensive in most places in Israel, however, there are ways to at least get cheaper junk food. In Geula, there is a store that has bags of popcorn hanging from the ceiling and they are at a really good price, I usually get the 14 shekel popcorn, and I buy sunflower seeds for my junk food most of the time and the popcorn lasts me about a week.
Clothing: If you need to purchase clothing, you should do it in Geula because it is much cheaper there. I have needed to purchase tights and skirts (after leaving the first seminary that I was at, a bunch of my skirts went missing, so I only had six skirts and they were the ones I never liked to wear/ packed because my mom wanted me to wear colorful clothing in Israel… so I have bought some replacement skirts in geula).
Sefarim: If your school gives you a list of what you will need to purchase before going and you see that you already own some of the seforim you need, then you should bring the ones you already own so that you don’t have to spend as much money on sefarim. Some schools have the option of borrowing sefarim you need for class for a token fee, but those ones might not be in such great condition.
Traveling: You should make the best out of your seminary year by visiting different parts of Israel on shabbosim. I spent a shabbos with my friend in Haifa, and even though it was expensive to take the bus there, it was totally worth it because I had an amazing experience. Just keep in mind that since you are in Israel, that busses need to stop with enough time for the drivers to get ready for shabbos, so make sure you leave early when going out for shabbos.
Buses: See traveling.
Family: Make sure to see your family! They most likely want to see you! Even though I am not so close to my relatives that live in Israel, a bunch of my cousins planned their visits for this year because I am here in seminary. That also makes it easier to have people bring me things that I need…
I hope this helps.