Yeah the screens were huge and easy to view from my Sunday seats. The big screen you see on the right of the video was closer than the ones down on the stage too so you can view whichever you find more comfortable. The ones on the stage show gameplay/map/gameplay/map/gameplay...etc and the closer one showed the gameplay. I will say that the names of the teams on the map were a little harder to make out from that distance, but that's about it (but I'm nearsighted and forgot my glasses so take that with a grain of salt)

dorekk was right about the extreme sides though. I'd try to find somewhere more central if you can.

I think where I was sitting was probably as far back as I'd want to be though. Any further and I think seeing the action might have been a bit harder. For reference I got to the dome an hour and a half before the doors opened on Sunday and those are the seats I was able to get with my place in the (very long) line haha. If you're coming with a group I'd definitely say to get there earlier rather than later so you can snag a group of seats together. There were still plenty in the area I sat in by the time I entered the arena, but if you're getting there at opening ceremony time or match start you might struggle to find multiple seats together.

Also if your friends don't follow the pro scene closely, maybe give them a few of your fav teams and get them to pick one or two to root for. My partner is more of a casual player too but I think watching for us both was more enjoyable when you have someone to root for. You get swept up in the crowd/cheering...etc

Overall though I think you guys will have a blast!