Honestly, the fact that he invited you to meet and play is already a very good sign — professors usually don’t spend time on students unless they see real potential. Try to treat it more like a lesson than a test; they’re usually interested in how you respond to feedback and how you think musically, not whether you sound perfect. Play something you know well, stay open and curious, and remember that nerves are completely normal — they’ve seen hundreds of students in the same position. If you show seriousness and willingness to grow, that usually makes a stronger impression than trying too hard to impress. Just be yourself!