Goto views and edit your view, select the block or page you want to edit template. From the Basic Settings, select Theme Information, there will be a list of output files like style output, display output etc. Select the area you want to modify, and copy the name in bold and goto sites/all/modules/viwes/theme; inside you can find appropriate file in it, copy the same and paste it into your theme folder, it is having the extension tpl.php back to views select the last given name in that block of output theme information and rename the file as it is. make changes to tpl and save.
First you have to download firebug (mozilla add-ons) and use it to find class and id of your blocks and views. Then styling them by css in your style.css file or local.css. Without firebug or similar browser add-ons, you can do nothing.
You could optionally set classes in views. Use those classes to style your views, it's pretty easy. Set a class of "myclass" Style like this .myclass { codestuff: values; codestuff: values; }
Well it's possible to do it without firebug if you want to try to wade through the existing CSS and page output (Ctrl-U) in Firefox and try to match it all up. Don't know why anyone would want to do it that way though.