How safe is my Nexus 6 with Android 7.1.1 and the possible latest update (Oct 5th 2017)?

I found my old Nexus 6. No SIM in it, just connects to the Internet via my home wifi. I've tried to catch the latest updates, upgrades, and security patches, then I realized, unless I doing something "big" like changing rom, or whatever it is called, which I definitely do not want, I stucked with 7.1.1 and its latest security update Oct.5th 17. My question is it safe to use? Nothing special sensitive there, but I would like to log in to Google Play with my account to download and by some apps