Welcome to the forum, Jacquie!
Best oft-repeated advice I hear is to focus on using the trailer for a while before starting major renovations. Clean it thoroughly, make sure it's roadworthy (lights, tires
, bearings), and get out and camp. Experience will help you prioritize improvements.
, with trailers we go by age, not appearance or treadwear. There is a date stamped into the rubber on the sidewall (read as WWYY = week, year). If they're more than about 6 years old, time to start over. The usual advice for bearings is 12K miles or once a year. Unless the previous owner can verify that it's been done recently, best to get it done- any garage can do it, doesn't have to be an RV shop ($$$).
Have much fun with your new trailer, and post pictures!