OK Tires, looks like you've already identified some of the things you need to do first already.
You need to get yourselves kitted up - you can't play without markers!
You need to find somewhere to train, like a local site that allows walk-ons.
You need to get an agreed training day, you can always have your team meeting for other stuff there after playing.
You need to find someone who will teach you to help you improve. I know no-one really does well at their first tourney (once you get there) but someone who knows a bit & can pass on suggestions while you train will help ensure you have fun rather than slaughtered in an embarassing way.
Once you've done all the above, you can start looking at local tourneys. Look out for something small, preferably at a site where you know the owner or other teams that play there regularly so you can be told what the normal routine is. Don't think you can go out & win Novice at the Campaign Cup first time out, as winning one game at your first outing will be a good result.
I think Smally is being a bit premature to talk about sponsorship before you've even played one event. Some teams go years without any real industry assistance. The best you can probably hope for before you get some trophys under your belts would be team discounts at the big stores, e.g. 10% off 'cause you're buying 5 or 7 jerseys, or a few quid off a case of paint if you buy 10.
Keep posting here & asking advice from the more experienced players, but I suggest you put a couple of specific questions up as & when you find out you don't know, as people are more likely to answer those that just a "tell me everything I'll ever need to know" type query.
And good luck! It's not easy starting a team from scratch, especially if none of you has any experience to start with. Be prepared for some to leave as the demands on their time & money get too much, but there's always more players out there looking for a team.