Timberoo saidA single date isn't much of a commitment. You have no obligations other than to be polite and honest. You might at least gain a new friend.
I agree. [To the OP] Take a chance, see how it goes. An older guy might be a treasure-trove of wisdom & experience he can share with you. And BTW, my partner is 14 years older than me, which is LESS than the age difference between you 2. Of course I do realize at our age that gap is less daunting than when you're just 20 like yourself.
Ya know, every date isn't an engagement to get married. It's the way you learn and gain experience, so that when Mr. Right finally does come along, you'll know him. And so you'll also know Mr. Wrong, too, if he happens to cross your path.
And here's the best part about exploring relationships, and building up your personal knowledge base: it can be a lot of fun! I've met lots of guys who simply became my friends, even though we soon knew we weren't going to become BFs, much less lifelong partners. It beats sitting at home! Just relish the pleasure of meeting other gay guys, maybe doing something intimate with them (safely), and simply enjoy life. At 20, it's all before you.