Mobily, Zain or STC are the big three. However, you won't be able to get a SIM in your own name until you have an iqama (residence permit) and that will be tied to your fingerprint too. Before that, your company may set you up with a SIM that is registered to someone else, but they will have to top it up for you.

Best bet for lots of Internet when you first arrive and have no SIM is a coffee shop with free wifi. SHouldn't be too hard to find.

I use Virgin for my phone which I've found always gets an excellent reception. For the home wifi I use Mobily. It's 150 a month unlimited. Works fine.

I have an STC portable router and Zain on my phone, the chances of both being out of service is about 3% of the time. Sometimes one service can be off/bad for weeks at a time in a certain location, if that location is your neighbourhood it can get really frustrating.

A coffeeshop for single females in Hofuf ?

Never been there, but if they have family sections in some of the coffee shops in the land that time forgot AKA Buraydah, which they do, there's probably somewhere in Hofuf methinks. Kind of defeats the point of going out though, to sit in a booth with the curtain pulled across. But free wifi is free wifi...

They let women into coffeeshops in Buraydah ? Decadent ! What would
Muhammad ibn Abd al-Wahhab say ?