If you're new to bike stuff you're probably better off buying something cheaper. If you spend a lot of money on top-end gear only to find you don't know how to look after it properly you either create a huge headache for yourself if your expensive new toy breaks and you don't know what to do with it, or a huge expense if your expensive new toy breaks and you have to spend a lot of money on having it repaired or replaced.

Start with something you can learn about easily, the kind of thing where if you break it you can just go and buy another one. If you wanted to start out with motor racing you'd be better off finding yourself something like a 2012 Ford Focus RS that's in good working order, than a 1994 Ferrari Testarossa that's got some rust and an occasional misfire. The Ferrari may go faster but it's going to cost you a lot more money unless you really know what you're doing with it, in which case it might still cost you a lot more money.

Truing a wheel isn't difficult unless there's something wrong with one or more components of it (which is always possible when buying used from an unknown seller). That doesn't mean it's necessarily quick - you need to make sure it's laterally true (i.e. you minimise side-to-side wobble), radially true (i.e. it's round rather than slightly egg-shaped), and correctly dished (i.e. the rim aligns with the centre of the hub rather than being off to one side or the other). Adjusting anything changes everything else, so if you adjust a spoke to correct a lateral wobble you'll change the roundness of the wheel slightly, and if you adjust a spoke to correct the roundness you'll change the lateral trueness.

I've worked on a couple of trashed wheels for practise (stripping down a wheel into rim/spokes/hub and then relacing and retensioning) a few times and built one wheel from virgin parts having had the practise with the trashed wheels. Building my first wheel took me four hours; the first time I assembled the parts from one of the trashed wheels it took me the best part of three hours just to get all the spokes in place and correctly laced, then several more hours fiddling with spoke tensions to get it radially and laterally true, at which point I found the dish was about 1/10" off and I had to readjust everything again.