How long you usually schedule for each (I'm sure depends on how many players)?
How many categories you offer (For each type)?
Do you personally buy the snacks and give them out for free (Fundraisers)?
For your first tournament you should probably just run 1 event (usually T1-2p). Figure out how many people are coming and how many rounds it will take to have 1 undefeated player. 4 people = 2 rounds, 5-8 people = 3 rounds, 9-16 people = 4 rounds, etc. Then plan for about 1 hour per round, but have time limits on rounds that are less than that (~50min). The extra time will get taken up by deck checking at the beginning, and a little downtime between rounds.
For your second tourney, I would add either T1-mp or TEAMS as the second category. For the third tourney I would either add the other one, or Sealed Deck (only if you know that people will pay the extra money to play Sealed). All 4 of those events are pretty simple to run, and don't require buying a lot of merchandise (except Sealed). If you are going to run a Booster Draft, I suggest attending another tourney that has one first so that you can see how they work. And I would completely avoid T2 until your playgroup has quite a bit of experience, and has had plenty of time to build up their card collections.
As for snacks, I usually have some food free (chips and soft drinks for Fri nights or doughnuts and milk for Sat mornings) and other that is cheap for people to buy (half a pizza for $3 for Sat lunch).