Honestly, my suggestion would be to enjoy yourself in the present moment. A bike ride sounds like a lovely first date. It can be overwhelming to think about the expectations that go along with dating sometimes, and I can understand your fear. I would suggest letting go of all that and just being in this person's presence. If physical contact comes up, I would suggest being honest: that you aren't sure your ready and need to take it slow. It's important NOT to push yourself on that point; otherwise it will backfire spectacularly. Listen to your heart and your body and maintain the boundaries you need to maintain to be comfortable. Physical contact doesn't have to happen on the first date for it to be a good date. If this is someone who can hold a good place in your life, he'll understand and respect that.
Good luck and
PM me if you need anything else.