I agree that for your first TT you should look at used. Most new buyers find that during the first year they figure out numerous things they don't like about the TT and usually trade it in on a different model so they take a big financial hit. Buying used you can usually find a reasonably priced trailer, try it for a year and if you decide to sell you don't lose that much of the initial investment.
Since you are by yourself or even if you have a partner you probably don't need a trailer with bunks. Single or double axle and length will depend on what you like for living space. By staying under 5000 lb. as you mention, your 1/2T will be plenty and haul it without problem.
I would suggest you get a weight distribution hitch with sway control and learn how to use it properly.
When buying used, inspect the TT for any signs of water damage, make sure everything works, check the tires for age, sidewall cracking, battery, any damage, age of propane tanks, They will eventually need to be tested and recertified but not too expensive. If unsure what to look for take a friend or TT mechanic who is. Buying something that needs a lot of repairs can be a bad experience for a new camper.
I hope you enjoy your new to you trailer experience
