I meant how much should I charge to develop a website?
How do I decide this being a freelancer?
You are still asking a fairly open ended question. You can do it a number of ways, cost per hour, cost per built item, a combination. I would look around at freelance job postings and see what people are asking for or offering their services for. Figure out where you fall into those ranges.
A place to put bids on jobs.
Actual jobs of various types(full-time, freelance, internship)