Short story ---
A slightly longer story ---
A few years ago I had designed a website for somebody, and a few months later they decided to update it, choosing to go with a different designer. The new designer and I knew each other, and I received an email from this person one day tearing me completely to shreds. One thing that really stuck out for me was a comment made regarding my PHP skills: "Unless you are absolutely fluent in a particular in programming language, you might want to remove that boast from your resume." So of course I interpreted that to mean "If you don't every little tiny thing about PHP, and if you can't write it in your sleep, don't bother even mentioning it to clients at all."
I don't know if that's how they meant it or if that's just how I interpreted what was said, but that one line has always loomed over my head. Over the past few years though, I have worked with PHP more, and though I would not consider myself an expert by any means, I would, on a scale of 1-10, give my PHP skills a 6 or 7. I can't write my own code, but I can certainly work through pre-written code and edit it to suit my needs. I know how to use PHP includes (I use them all the time), and I know how combine variables with form fields to create submission forms, and I know how to stylize those forms so that it looks nice when the recipient receives it, my contact forms also mails a copy to the sender for their records. I'm currently working through a series of video tutorials to learn about PHP more in depth.
So yeah, sorry for the novel, but I just wanted to give some background because I know just asking "How much experience do I need?" would warrant responses like, "Well, it all depends". I want to be able to add these two things to my resume because that would open up a whole new world of clients and job opportunities for me. But I worry that if I mention these things, I might get a client who needs something totally original that I'm just not capable of creating, and I don't want them saying something to me like, "You say you know PHP and you can't write this code for my site?". Basically, I don't take criticism very well because I always take it so personally- I feel like it's an attack on me as a person rather than just on my skills (or potential lack thereof).