Your question not clear please. What exactly do you need help with about UX? Want to rework on your website to improve user experience, you need some feedback on your user experience? Providing further help will let us give better thoughts.
One of the cheapest ways to do this is to use the same people who developed the site. This is not always ideal because they may not want to undo things they've done, but the knowledge base is there to fix bugs.
You can simply look at the site yourself. Use different devices and browsers. Ask your family and friends to take a look and report anything...
Spend a week doing this. Make a list of 'bugs' and let your developers handle it.
Ultimately, you don't need to be very technical to get the site correct.