There are lots of different "debating" themed games to help you improve your debating skills.
Here are a couple of my favourite:
The Hot Air Balloon Game
In this game everybody chooses a character to be - fictional or non-fictional - and then have a minute or two to explain their charcter to everyone else playing. You are all on a hot air balloon that is damaged and is falling down because it is too heavy. Only one person can be left on the hot air balloon to survive so you have to try and convice the others playing to keep your character on the hot air balloon. After the introduction, there are multiple rounds, each consisting of arguing why your character should stay on, and then a vote at the end of the round to throw one character off the hot air balloon. This is repeated until there are two characters left on the hot air balloon. They have one final debate before all the thrown off characters return and vote for which character should stay on the hot air balloon and win the game.
Four Corners
In this game a statement is made (for example "this house believes pineapple does not belong on pizza) and then all participants must go to a corner of the room, each corner labelled Strongly Agree, Agree, Disagree and Strongly Disagree (they could also decide to stay in the middle if they are split). Particpants must then - once at a corner (or the middle) - give some reasoning to why they decided to go to that corner. Players may also decide to reply to one of the other reasons made by arguing why it could be wrong. This can be repeated as many times as liked with new statements each time.