I would go to system; security Virus and Malware detect and repair.
Then try Wi-Fi again, sign in with the password for your Wi-Fi. Once
you have your puter ok then try the same stuff with the tablet.
Auto connect is in system; System, Home, Internet Wi-Fi Auto Connect page.
It may need shut off and then back on.
Maybe peruse thru System and Home pages, not changing anything until you refamiliarize yourself with the functions it offers you.
Size of screen, sound, Anti-Virus downloads, lock screen, themes, background, that stuff. Do a scan of available Wi-Fi networks,
select yours, enter password that should get you up and running. Your tablet may need the lil micro-SD card installed in it.
I needed them for my I Pads. At& t, Verizon, etc.
The name of your system and PW should be inside the box, on the Wifi and card?