Freedom Seeker

Hi, Ok, so I'm 40, and this is probably a mid life crisis, but I'm gonna do CBT next month and have my heart and mind set on a Yamaha DT125RE (Black). I was gonna go for a Honda XR125, but then I saw one on the road, and they are really short. I'm 6'2", and I think the 900mm seat height on the DT would suit me fine. Anyway, I'm getting mixed messages about the premix situation... after hearing its a pain in the arse etc, I then heard that certain bikes use a pump of some sort to do the premix thing for you. Anyone know the details? What models have the pump thing? Does it work? Your thoughts. Also, I'm gonna take this opportunity to get some basic mechanic skills behind me. Can anyone suggest some basic tools to start with just for the standard maintenance tasks on a DT? Another thing. I am soooo worried about buying second hand, especially about if a bike has been run in properly. Is this something I really need to worry about? What other blindingly obvious things should I look out for when buying second hand. Please be aware.... I AM A TOTAL NOOB! Regards FS