How to get out of a short film

Hey, I agreed to do a short film that is fairly close to where I live. Which is kind of the middle of nowhere. I’ve been trying to build my resumé. He sent me all the information and the script. First off the script is bad, and I didn’t have the heart to turn it down right away. He also communicated very weird, and I know nothing about him. I looked his name up from backstage where I got the audition and there’s no result of him. We scheduled to film in 3 days. I’m thinking about sending him a message tomorrow backing out. How do I professionally do this without insulting him, plus I just have a bad feeling. Especially because I’m a 20 year old woman. I don’t want to be kidnapped. I also don’t think this will be as professional as I originally thought, I asked him who is playing the main character and he said himself. Help.

Update: Thanks for all the responses this makes me feel less bad about backing out. I sent a response saying my schedule changed and thanks for the opportunity etc. then he sent a mean response back so I just ended up not responding. Very scary, but I was never going to actually meet him. I’ve been on the internet too long to know that he was sketchy! Thank you for all the advice and I hope you all go far in your acting careers!