Advice on a 5ish year old Haflinger, not broke...?

I recently rescued a 5ish year old Haflinger, who we discovered is not broke to ride...He seems decent with the farrier and clipping. Does not do well with baths, and when we tried to put a rider on, he definitely did not like it! When we put just a western saddle on, he stood somewhat but was still very uneasy ... Another thing he does is pawing at the ground when in the crossties, which he is waaaay better at now, but was another clue at his lack of training. I would just like some advice on maybe breaking him to ride, some groundwork to work on, help curbing bad manners...I have a trainer who will be helping me in a few weeks but I would like to start on some things now, so he doesn't think I am going to let him get away with things! Thanks in advance.