Where to move in Thailand?

I'm moving to Thailand in January for my Muay Thai training. I found a gym in Pattaya I like, but I don't know if that will be a good place to live? It seems dirty to me at least that's what i hear. Are there any nice clean girls there or is it mostly dirty ones. Don't want to get caught up in all that while training. Thought about Bangkok but it might be to big and Pattaya is cheap. Any suggestions will be great. Thank you.