Hi Andi, and welcome! You certainly found the right place if you're lookin' for support, nice people, and lots of info...
As for your questions, I don't want to overwhelm you with too much info, but basically, the two forms of Medifast are "Full Supplement" and "5 & 1." The difference is that Full Supp means you eat nothing but MF foods for all 6 daily mini-meals; on the 5 & 1 plan you eat 5 MF foods and also one "lean & green" meal consisting of real food-- for women, 4 - 5 oz. lean protein plus 2 cups of salad or 1.5 cups of cooked veggies.
You can order from any place you like; there are several sites you can use and many health advisors (people who are trained on the ins-and-outs of Medifasting and who help you succeed, answer questions, provide support, etc. when you need it). Many of us who come to this board order through Nancy and Terry's site because the cost to us is the same, but the credit for the orders goes to the Dream Team who host this site. (They're too nice to plug this themselves, though!) If you do want to order thru Nancy & Terry, you can just go to the makemethinner dot com site and look for the "Shop Now" link. Or you can just send an email directly to Nancy (look for any of her posts and click on the "email" link below her signature) and she'll help you figure it all out.
The "starter kits" people talk about are basically a collection of 2 weeks' or a month's worth of Medifast foods, plus a written guide, that you can buy all together to get you started. You don't have to do it this way, though- you can just figure out how many weeks you'll need to "feed," and make sure you order enough of what sounds good to keep you going-- you'll need 5 supplements a day, and they can be any combination of soups, oatmeals, shakes, etc. Just remember-- only one *bar* per day, because they're higher in carbs. You can also have one packet of MF crackers per day, too-- they go great with the soups. Other allowed snacks include 2 dill pickle spears, 2 cups of bouillion (or 2 MF Fast Soups (instant, lighter soups MF makes, meant for snacking, not as a meal)), and 3 stalks of celery per day.
You should also make sure you read carefully the "FAQ" that's posted here at the Forum and on makemethinner dot com (I hafta spell it out so Mr. Snippy doesn't edit it out!). It will answer many questions...
Anyway, you have some reading homework to do!
We are here if you have any questions, and I hope you find a home here... Lots of folks here have had experiences similar to yours, and many of us have a long way to go, so you're in good company!
Wishing you the best!