Attraction sometimes occurs over time. Many people have said that it was not love at first sight when the two people met. However, some people like being friends with each other and the love grows over time. Therefore, it is not wrong to go out with someone who you are not initially attracted to them. However, everyone should be aware that you want to start out as friends.
I would not recommend that you tell the other person that you are not attracted to them, but tell them that you would like to start off as friends. Throughout the weeks of being friends and going and doing things together, you can re-evaluate your status with this other person. At some point, you may find a stronger attraction to them.