I'd strongly suggest you buy a new one. You can get some ones at good prices now, and there could be all sorts of little niggling issues that you may not be able to easily fix with a laptop.
Note that you'll be paying more for a laptop than a desktop, and you can't easily upgrade them like you can a desktop.
Yes they can be plugged into everything. The only thing to watch out for is that they have less USB ports etc., then desktop machines so you may find a USB hub useful to extend the number of ports you have.