Joomla, templates, hackers

I am new to DH and designing with other apps besides Dreamweaver. I installed Joomla in the wrong directory, my home directory, and want to move it to a sub directory. However, I want to use the application to design my website. Should I uninstall it, seems to take more effort, or should I just move it?

Does anyone know of a good source where I can get good templates to use with Joomla or with Dreamweaver?

I went to my website today and saw that it had been hacked! How can I avoid this in the future? It is not clear to me how it was done.