I think most people have tried to answer how it will feel and what you can do. I'd be interested to know why this is the guy you want to give your virginity to. Is it because he's attractive? Is it because he's really nice to you? Is it because of how he makes you feel when you are together?
The thing I'm concerned about is... you want to have sex BECAUSE he is huge. Like, you want to be able to brag about the first time with this huge guy. Maybe I'm wrong, but that seems like a crazy way to choose your lover. If you had already had sex and wanted something bigger and more satisfying, I might understand you wanting to try his huge tool. But, not for your first time. I'd re-think this idea.