How do you tell what degree it's set at, it came centered so I'm guessing it's zeroed out for now

 

If its the stock advancer there is no adjustment. You can buy aftermarket advancers that have timing advance built into them but still not adjustable. Or an aftermarket advancer that is a two piece sandwiched together that is adjustable. Also in the Clymer shop manual it tells you what the timing is. Example "X degree before top dead center" something like that.