A proper noob question here for you guys!

Does anyone have any tips/techniques/ideas or things you do when testing new equipment and guitars?

I'm talking from a fairly untrained point of view here. I've been playing guitar for a good few years but after the initial couple of years I seriously slacked off and now I've decided enough is enough and I want to get back into playing properly.

As a result my ear and techniques are seriously rusty.

I'll probably be buying from a local store

I'm gonna be looking at modeling amps because I want to be able to as much in terms of different styles as possible (metal being a predominant style though). I'm looking at new equipment with a budget of about £300 (most likely one of Peavey Vypyr, Vox Valvetronix, Roland Cube and Fender Mustang)

I'm also gonna be trying out guitars as well so any ideas or things I should be looking for with them would be greatly appreciated as well.

Thanks for any help!!!
Just try to play a wide variety of stuff. As far as amps go, I think the newer valvetronix + isn't as good as the original one.