Welcome to the Upwork Community! I would recommend that you visit the resources we have compiled for freelancers and clients in this post for more information on how you can start hiring successfully on Upwork. I also did a keyword search for "hiring tips" in our Hiring Headquarters which you may want to check out. Here's the search result link.
I hope this helps! Please don't hesitate to reach out here in the Community if you need further help with anything. Good luck, and welcome to Upwork!