I'm guessing you're doing under-saddle trail? Not led, because we only have young horse led trail.
Its really important not to rush anything in trail, because a judge looks for a willing, alert, obidient (sp?) horse. That doesn't mean your horse has to be slow, it just means that if your horse wants to look at the bridge before he goes over it, then you should let him. Provided he doesn't sniff it for too long, all should be good.
Most trail courses also have a lope over pole. Work on him loping over a pole, not jumping it. All you need is a ground pole like you use for the L's. If you're going to a big show, they decorate the arena with bunting, and pot plants and lots of ribbon etc. Its really important that they're desensitised to that because I've seen horses spook at Nationals or try and eat the plants when they go over the bridge.
Can he side-pass? Thats really important for opening gates and sometimes they might make you side-pass the L.