Hi, and welcome to the forum. I'm guessing that you are hearing some hitch noise? Make sure to apply a little grease to the hitch ball to help keep that quiet. I'm not real familiar with your model, but mine came with Dexter axles and hub assembilies. They have a pretty good website at www.Dexteraxle.com
that will give you all the literature on their hub assembilies including maintenance schedules and grease specs. I would hope that brand new bearings would've been greased properly from the factory, but stranger things have happened. If it seems like the bearings are noisy, it may be worth the piece of mind to pull a wheel and check them, I usually do this at the start of each season anyway. Also, you can check the hub temperatures, after you pull for a little while, to see if one hub is heating up more than the others. Keep in mind the brakes will effect this more than the bearings, but just another tool to help watch what your trailer is doing. Happy camping!