Hi Mary,
I can't help you with any ideas on a suitable ISP as I live in the UK. However, I'd agree with those who say don't go with the free sites with adverts.
If you want to use a site to sell your gigs, its important to look professional. Free sites with 'pop ups' don't.
As far as HTML is concerned:
YES you can write webpages without learning HTML, but they won't be great.
You can call yourself a 'guitar player' by knowing 3 chord shapes. Learning a bit of music theory is likely to make you a much better guitarist.
It's the same with web pages. Understanding what's going on in the background is really important if you want to create good looking pages.
You can drive a car without having a clue about how it works, but its not great when the car breaks down.
It's the same with web pages. Webpages aren't like word-processor or DTP documents, they don't look the same way to everyone who views them. What looks great on your computer, may well not look great to a reader using a different browser, different OS and different screen size.
Learning some HTML basics really helps, and it's pretty straightfoward too.
I'll post some links to (what I consider to be) some of the best resources if you are interested.
Ed