First off chess timers are normal but only for tournaments or if people are practicing for tournaments will some times use them as well. In normal casual games at a
LGS people generally don't use them. There are two different formats for tournaments: one is timed turns where you get a set amount of minutes per turn as well as a round timer and the other is death clock where you have a set amount of time and if run out then you lose. I wouldn't worry about this right away unless you want jump straight into playing at cons and tournamentsf, and once again people don't use them in casual games generally.
I don't play trolls but I know the krielstone unit is stable in a lot of lists and you can't go wrong with a lot of melee infantry with madrak like warders or kriel warriors. I know trolls a faction with a lot of inbuilt synergy with lots of buffs to make the infantry shine.
I look take a look at
battlecollege. It has descriptions of all the units, no stat lines or anything.
I did come across an articles on Muse on Minis awhile ago about starting trolls you may want check that out as well.
link link
Edit: Also I would shoot for 35pts rather than 30. 35 and 50 are the point levels where Warmachine is commonly played.