Speaking to ATC whilst you're flying can mean all sorts, from position reports to joining the circuit. IMHO the radio work near the airfield is the easiest. Were you to start at an A/G field you would easily learn how to talk to an ATC. And as has been said, the benefits of A/G are many, mainly culminating in less cost overall, or more time in the air. Never fear talking to ATC. As long as you have learned the book they will be patient and accomodating.