As many have said, make sure you buy a good set of "new lensed" goggles be it second hand or brand new, always make sure the lense is new, this is standard before you go buying a paintball marker.
As for a marker, it all depends on what your looking to spend, you can buy markers from £50 up to well over £1000, now im assuming "always a bad thing
" your not looking to splash that sort of cash and are looking at maybe spending up to £300 ?
If so, you cant go wrong with an EGO 08 or an EGO ETEC, really really reliable, shoot as straight as anything out there, very very efficient and most importantly there is great support for these markers, i.e. parts are easy to get and there is alot of people that can help sort any problems with it.
You can generally pick up a decent second hand one for around £300 or less on these forums.