Which Freelance Website is best for Pick the Project?

Google it, there are loads to choose from now. I've had mixed experience over the years trying different sites, but freelancer seemed ok. Just remember you get what you pay for.

There is also upwork which is very good. I use it often to get work done.. Fiverr is not so good any more, it's popular 

Did you receive the payment from Upwork for your works?. If yes what are the formalities they follow and do you face any difficulty?.

I tried to get work on UpWork and found people wanted the moon on a stick for the price of a stamp. So I left. 

I was a buyer so to speak..Used to use it for my Zencart website when I needed work done. Never had a problem though and ended up using teh same guy for ages . But as Rebecca  says everyone on these sites are looking for a bargain so to speak.. Although funnily enough I am looking for someone to build a module for my website as we speak, just trying to find other people who are in need of the same module ,so we can crowd fund