Yo man, DO NOT develop sites for free!
You can develop them for "not or cash/money payments" but NOT for free.
Do not undervalue yourself!
If you want/need experience, try starting instead on modifying existing sites.
And don't gulp down wordpress nonsense either: Wordpress is an operating system of complexity (with far worse organization) used mostly to put-up banners.
I'm new, and I hate to just jump into business junk, but I was thinking of doing this too for a moment till experience kicked me in the head to remember.
DO NOT under-cut your value. If you need experience, work with other devs/programmers--help them if they'll help you...
Notice again, NOT for free: YOU ACTUALLY CAUSE A BIOLOGICAL devaluation of yourself in their minds EVEN IF THEY *CONSCIOUSLY* like the idea of someone motivated enough to buy/earn their way into the business.
It's like the stuff people here talk about with women: you THINK something is "rational" (and it is) to do with women, but it has awful unintended consequences on a secondary, tertiary level or beyond.