I don't think you can even bring a firearm into most public places, so maybe that makes things safer, as long as you don't notice a bunch of people suspiciously placed somewhere outside near the venue and watching you, as that may be a sign of a kidnapping.
The pocket knife is a good idea though. Good luck on your trades, and hopefully there are people around your area looking to do business with you.
NotATether has a very important point, no matter how careful you think you are being, pay attention to every detail, regardless of the platform and the reputation system it offers, always check the profile of the person you are negotiating with, do some research on the agreed location, always choose to go with a friend, inform the other party about this, say it is for your safety and see if they agree.
I have never done f2f transactions because there is no need yet, at most I already use bisq, but for online transactions. It's challenging to find someone willing to do f2f transactions.
If you can leave us feedback on the solution used for your negotiation, this will help us evaluate the platforms before recommending them. I'm also curious to know about and carry out this type of negotiation when necessary.