#1
So I've had lessons for around a year now with a couple of different teachers (due to circumstances). I can manage myself in a song requiring clean vocals but while they're nice they're not the only thing I wanna be able to do. I wanna be able to scream, with a scream similar to how Dave Grohl does it. Thing is I don't know how to start doing that or if the technique's the same as metal screaming or if my being a baritone has anything to do with it.

Anyone got any tips or lessons as to direct me on where or how I should start?

Thanks!
Current Gear:
Peavey Zodiac DE Scorpio (Bass)
Yamaha RBX-170 (Bass)
Boss ODB-3 (Overdrive Pedal)
Line 6 LowDown 150 (Amp)
#3
I don't know much about screaming. Seems like a good way to harm your range as a baritone. I would probably look at electronic augmentation there. As a baritone or a bass singer remember when you are harmonizing you usually stick to the melody line. If you play in the keys at the extremes of your range, your range will increase.
#4
Go way out into the country, and practice screaming at the top of your lungs.

Just do not overdo it.

Start out with small screams, if that is possible.