I’m in a worse case than you, I don’t even have a penis.
On a more serious note, don’t let size fool you, I have had sex with men with big dicks and it sucked because they relied on their size to do all the work
They wouldn’t even move, they wouldn’t do anything, they would just stay there and probably think “my big cock is good enough”
Just make sure you have size appropriate condoms, the person you’ll meet might have some if she’s a professional girlfriend
Don’t overthink it, you can also work on your clit stimulation skills and oral (if you do that)