Is it safe to do a Software update for a Brandnew Galaxy Note5

[AC Question]

I started up my new Galaxy Note 5 on Friday and have just been personalizing it over the weekend using Wi-Fi only. (My SP did not send the new Nano Sim Card with the phone). On Sunday evening a Software Update was downloaded either by itself or me not noticing what I was doing (??) Now the Software Update has to be installed but I am scared that I might be disappointed afterwards. Either loosing music, mails, contacts etc. Will it be safe to do the update or if not how do I remove the download then?