Newbie has a question???

Hello all, i found this site a day or two ago and i’m on here religiously everyday an i absolutely LOVE it here. I try to go to as many forums as i can to learn as much as i can. I’ve been reading the post here and i’m confused about a couple things. I’m new and i’m starting out just property locating . I see that you guys are talking about finding property, let’s say for 30,000 and putting it under a lease option or is purchse agreement contract for a couple of months. Find a buyer and sell it to him for 50,000 and BOOM get your 20,000 minus closing costs?.
Well is my understanding right or wrong?

So if i don’t find a buyer, am i free?

Do sellers ususally require you to put a deposit down or do you do this without risking your own money or credit?

You would probably want to have an BIG buyer’s or investors list built up before you do deals like this right?

Is this agreement giving you the rights to sell the property for what ever time the contract says?

I’m trying to learn all aspects of the industry and ways of making money. Any responses would be appreciated. Thanks!