New things take time to feel familiar.
Your confidence will grow with time, and driving will become second nature to you.
Tailgaters are so rude, but you can signal a turn and pull over so they can pass. People expect to be able to do the speed limit, plus some. Actually the speed limit is the upper limit and not the minimum

Keep practicing, that's a great idea. Maybe go out during times when there are not many cars on the road, keep your cell phone nearby to remind you that others are easily contacted.