I have an autistic friend that makes me feel uncomfortable sometimes and I don't know that I want to be close friends with them anymore.
What things does your friend do that makes you uncomfortable?
Sometimes when we are talking, they just space off and I feel like I need to move on from them.
Most autistic people don't have a lot of friends and can sometimes feel uncomfortable around others. I am sorry that you sometimes feel uncomfortable around them but I don't think you should stop being their friend all together. Maybe you can stop spending so much time with them but still manage to see them occasionally to do something with them.
I just want to be friends with cool people.
Cool people is subjective. One would find someone cool while the other uncool.