What you have to do is go into your control panel, probably cpanel or other, and install from there. Just have a look at the control panel and spend a bit of time getting used to it.
After you have installed wordpress from there you can search for, and install templates. After that you edit the template wordpress with your content. DO NOT give anyone your password without a very good vetting. For example I could offer to help and login to your site, do a bit of work but install a backdoor or compromise it some way.
It really is fairly straightforward, the really hard part is the graphic design component... creating your banners, doing the content and actually finding a nice template!! VERY time consuming if you don't have that flair for it..