Hi, I'm new to this too but if you search you may be able to find beginner rides where they have a "no drop" policy. Basically they will not leave you and will even come help push you up the hill if you really need the help.
As for the pedals...I am amazed at how much easier it is to ride and how much further I can go by being able to pull up on the pedals instead of just pushing them down!! Don't be scared of them - they're an adjustment but if they were impossible there's no way so many people would love them!! I practiced on a trainer first - getting in and out of them...but be ware!! Pay attention to not leaning your body over when you pull them out of the pedals!! I was doing just that and didn't know it...the first time I got on the bike for a real ride I came to a stop and fell over!! I laughed more than I hurt - promise!!
Good luck!!! My boyfriend dropped 30 pounds FAST riding and he wasn't even trying to lose weight!!