What to do if I was in a an accident with a guy who was unloading a large trailer of bricks with a forklift and who pulled right out in front of me from behind the trailer?

Basically, the forklift operator may have been negligent when he pulled out in front of you, and the trailer's owner may also be liable if he was parked illegally. If you were driving your bike on the sidewalk, that could seriously undermine your claims, because that is an unsafe use of a sidewalk.

It is very important that you get your tooth fixed--that sounds like an injury that could lead to decay and further health problems if it is left untreated. From a legal perspective, it's your responsibility, not anyone else's, to prevent those kinds of future injuries. But more importantly, this is your health.

It might be a small hardship depending on your resources. If you can't afford it, you could explain to a dentist how you were injured and make a promise to pay him if you recover his bill. This is a common enough practice that it wouldn't sound outlandish to the dentist, and even a dentist who won't do it may know others who are willing.

In Texas, sometimes the government is "immune" to a lawsuit, but probably not in this case, and it sounds like you might have a claim against at least the contractor who was doing the renovations.

If I were you, I would document all of my expenses (including the relevant bills) very carefully and completely. I would also find out which contractor was doing the renovations that day (the government is usually obligated to tell you these things in Texas through an open records law, and certainly knows which contractor it was using). Also, I would go back to the area and see whether the trailer was breaking any parking rules--maybe the PD/library will know something about who had the trailer there that day (and maybe it was the contractor's trailer). And this is at a minimum--I would find out everything possible within reason.

You might not be able to get an attorney to take your case to court, because the damages are probably low in comparison to what an attorney needs to earn on a case. However, if you collect information as suggested, you might be able to send a letter (or get an attorney to send a letter) to the contractor and other entities, and they might reimburse you. It may make more sense for them to reimburse a well-documented but low-cost injury than to fight about it.