help making a file for me to load in dreamweaver

Hello I have the latest version of dreamweaver and I need to have my website that is currently live imported into DREAMWEAVER so I can easily edit and make changes my site is php based... However I can not let anything go wrong I need css and all layout to remain same when changing and uploading is there anyway you can make me a load file for dreamweaver that I can easily click to import my entire website and that way I can make changes or can you help me get this setup to work this way with dreamweaver I can not figure out how to do this. if you can tell me how step by step i can do it that way to I am ok with whatever as long as we get it to work so i can use dreamweaver.