Buying a PC for AoE 2

Hi guys,

I've been following the aoe-scene for almost a year now. I also managed to purchase the HD-version and play against the computer on my mac. But the moment has come: I'm going to buy a pc (only for are 2-purpses) and getting all the expansions and patches, and want to start playing on Voobly. There's only one problem: I'm a complete noob when it comes to all kinds of tech-issues, so here's some question I would like to get help on:

1: What kind of PC should I buy? What screen size do i need. I think I would like to buy a laptop, except that I don't know much. I would also like to keep it rather cheap since I'm almost only buying it to play aoe. I'm living in Norway, so if there's anyone from Norway out there with tips on where to buy it, that's also appreciated.

2: I've bought the HD-version on Steam, but when I got my PC up and running, I would like to play on Voobly (and with all the expansions and newest patches). How do I get to play there when I've bought (some of) the game on Steam?

3: Is it bad for me if I'm playing on wifi? I'm moving to a new apartment in a week, and I only know that we have a wifi there. I have never been a gamer of any sort, so I don't know how to play via cable, and if it's even possible with the internet that I'm getting in my new appartment.

If you guys have any other tips for a computer and aoc noob, they're all appreciated.

Thank you all in advance :)