This website has not only an exhaustive list of shortcuts but also gifs that demonstrate how they work. I highly recommend:
Miscellaneous Keyboard shortcuts I find helpful:
CTRL-T = Split region (make sure to select the region and then move the playhead to the point you want to split the region into two parts before you use this, otherwise it will not work)
CTRL-X = trim silence (for any audio region, will go through and remove any silences you have. Tolerances for what consistutes "silence" as well as how soon before/after sound to trim can be changed.)