I need some help, i've been reading articles on how to read drum tab i've printed off for Nirvana, my band switched songs, anywho, can someone help me out and explain/ how to's on what the following terms are?

Click Hi-Hat with foot
Accent
Flam

Source is: Here

Thanks to anyone who helps.

Also, if anyone has any tips on actually drumming Nirvana's "Smells Like Teen Spirit" please by all means, reply (I'm new so please try to keep the terms simple ).