I have a job interview coming up but I'm not 100 percent sure I want to work full time.
Why don't you want to work full time?
I am concerned I might not like it.
If you're unsure you don't want to work full-time, but the company is hiring you to, then you probably shouldn't go to the interview. The company might be really mad if they find this out.
They won't find out, I'm just scared. There is no point living in fear.
It is good to face your fears. If you show up you might actually enjoy working there.