When you want to offer to do something, and you're sure that the listener will accept your offer, say "I'll ___":

I'll call you next week and we can settle on the time and place.

I'll go pick up all the stuff we need.

I'll print out a few copies of that for people to refer to.

If you're not as sure that your offer will be accepted, you can say "I can ___ if you want.":

I can fiddle around with it for a while if you want.