How can I see what specific times my phone has connected/disconnected to wifi? I would like to see at what times exactly in the last week (for example) my phone connected to wifi. In fact I would like to be able to see an activity log of some kind? Would you be able to see location history if your location services were switched off, for example? Any help would be great :)
You can check the internal Android log
logcat to see WiFi connectivity changes (and many different events) from the last few hours or so.
To do that, you'll have to enable USB debugging, download ADB, install an ADB driver for your phone on your computer, connect the phone with a USB cable and run this in a terminal:
adb logcat -v threadtime ConnectivityService:* *:s
To dump the whole log to a file, run:
adb logcat > log.txt
However, if you need older data, the most bulletproof way is to create a custom app that would log the events you're interested in.
Here is a simple application for your needs. https://play.google.com/store/apps/details?id=org.rjj.android.wifimonitor