Changing my site design, dont want to ruin how it currently is though ?

picturebike

Hi smuggers

Im thinking of a complete change to my site, if i choose a new layout template can i do a complete re-design whilst the current design stays live ? Ideally i would like to play with a new layout over a few days to get 100 percent right before switching over to make sure im happy with it, can i save it as project before making a change over ?

Also will my current design be saved if i want to come back to it in the future ?

Thanks