Preparing for my first conversation with a native speaker—nervous about Keigo

I have my first real-world Japanese conversation scheduled soon and I'm terrified about accidental rudeness. I know generally that I should use polite form, but I often get tangled up between 'sonkeigo' and 'kenjougo' when trying to be polite. Should I stick to safe, simple grammar, or is it better to try and use the honorifics and risk making a mess of it? I'm hoping to use Chickytutor.com to simulate a polite-but-casual dialogue flow before the actual meeting.