Audiosnap will detect the tempo for you. For lining up the timing it might be as simple as stretching one of the clips. Hold the ctrl key down while slip editing.
If the timing issues are a little more complex then you can use audiosnap. Quantize to pool is helpful for that. Basically extract the timing from one clip to the "pool", and then apply that to the other.
For much more info on using Audiosnap and how to do it, see the
video here. Audiosnap coverage starts at chapter 37. (Select that from the playlist) and there are several chapters. Audiosnap is a fairly big tool with lots of options on adjusting audio timing.