Keep practicing. Everyone has to start somewhere. Ignore the mean comments. You should learn to drive with your feet. If you get into a sticky situation, you will need both hands on the boom controls.
They will keep rebuilding the dam. You have two choices, take the beavers out (trap or shoot)or get two runs of 40 foot 4-6 inch white or black septic leech line pipe that has all the holes in it and lay it over your dam, with a couple of 90 or 45 degree couplers so it stays under water and follows the line (drop) of the dam. Pin the pipe to the bottom with garden staples or use rebar stakes to keep it at the depth that you want under the water, otherwise they float. And you have to have the length or the beavers will just mud over the pipe and dam the opening of it. That will keep the pond at the level of the dam.
