So if I land on a character take there trophy, is that it? Or do I also attack the character or can I engage the spot. As well as take the trophy

You don't initiate combat or encounter the space when you choose to take a trophy. It is worded much the same as the Sorceress ability to take followers and the thief ability to take objects, so if you opt to take a trophy from a character you land on with the Bounty Hunter then that would be your encounter for the turn. (This is the reason that everyone in my gaming group tries to stay at least 7 spaces away from the BH whenever possible!)