So I have this neighbor. It's actually two, a man and his wife. Both are very nice, very friendly, but I don't really know them. In fact, my family knows them, but I've never personally been introduced to them.

I'm walking down the road to my home from my friend's house; I'm about a block from my house. My neighbor pulls up alongside me in his car and asks if I want a ride to my house. He's the only one in the car.

What should I do?

Now, assuming I get in the car, what should I say/do during the short ride?

If you have never been introduced to him, I would stay out of the car for sure. Just say you like walking.

Seems pretty silly to offer someone a ride when you know where they live and they are only a block away from home.
How about "No, I have to get my exercise. Thanks anyway"
If he offers again, just keep walking without words.
If you are a minor, you could cause him a lot of trouble. Don't get in the car, you have nothing to gain.

Well I guess one issue is how old are you and the same.
In general I do not advise people to get rides from people they don't know.

That is strange for him to offer when you are so close to your home. I would not get in the car. Just say thank you, I'd rather walk. Then I would ask my family more about him. If you have never been introduced to him, that is kinda creepy.

I suppose you should not take a ride with him because whatever he has relations with your family but if he is a stranger to you than you should not take any help from him.