One on each side. Easy DIY but you'll need an alignment after. Worst case is that a bad tie rod end will come apart but I think you'd have worse symptoms by now if self-destruction was a month or a pothole away.
You can do a quick visual check on the outer ends that are usually more worn. Turn the wheels all the way left and check the tie rod end at the back side of the right wheel. Do the same for the left wheel. The tie rod is the link between the knuckle and the steering center link. But if you don't know what a tie rod is then you probably don't know what a knuckle or center link is
At any rate, check the condition of the rubber boot at the end of the rod pointing at the back of the tire.
That thump could be anything -- wear in the steering damper, guide rod or idler arm bushing, etc.