Regarding accents... to me, accents are like icing on the cake, and I stink at em... BUT I think, in my humble opinion, that they are something to put on the back burner until a body feels comfortable just interacting with the crowd first. I can't remember ever having a spectator comment that my accent was off... now speech, slang, grammar etc... that is more important than the accent and yet tis something none of us would expect anyone to be perfect in any time soon... tis almost like learning a foreign language. Even the experts at places like Williamsburg don't have it down pat when teaching their foundation members how to speak.
To keep you busy if you like, try reading some period stories from the time frame, such as Moll Flanders, to see some of the slang and sentence structure ... learn some common words and start sprinkling your daily language with them... Aye, tis something others may look at ye fer.. but helps it does....
Again this is just my two cents, it is NOT required from any one...