I like Average Joe's advice.

Sometimes you need to read between the lines. The objections that people state are sometimes only a mask for something more deeply rooted that is the true issue to be addressed. What Joe says about listening will pay off here.

You're 17? Maybe ask your parents about helping you build a bike from the frame up. That would give you and your dad something to do together between now and when you are 18 that is bike related.

Ask your parents to join you in some group activities? Maybe one of those tours you are talking about? Your parents might feel differently about an organized event versus just randomly riding around. Plus they might find that they enjoy the event and want more.

Are there bike trails nearby that your parents would perceive as being safe? You might agree to limit your riding to safer venues, at least at first, until you and they become comfortable.

Parents like to do things w/their kids. Most of us. Ask your dad about getting two bikes and riding together.

Parents also worry a lot about their kids. Most of us. It is difficult for us when our kids hit their teen and late teen years and are branching out and becoming independent and going off with friends and we aren't around to keep watch anymore. I go through this w/my 19-year-old son all the time. He goes off to do something with his friends, and I worry. I was half in a panic when I brought him his bike at college so he could get around. Riding the streets without me? On his own? The thought was a difficult one. Your parents obviously care about you and are concerned over your safety, and they probably struggle internally with all the same things that I do w/my own son.