I've started playing it too

But apparently the spot I picked is the most boring place ever...
The only neighboring civilization are some other dwarves, the animals are all harmless, I haven't had any enemies pop up yet and my fortress is running quite smoothly so far.
Maybe I should just dig deeper and deeper, in the hopes of finding find some "fun" surprises in the dark depths of the mountain I've dug into :>
The second caravan should arrive soon (so I'm not that far into the game yet) and I'm at 50 pop.
Although if that is the magic number required for a massive goblin siege, I'm in trouble...
My only defense is a drawbridge that can block the entrance and some soldiers that I've just started to train up (they're not even novices yet), no traps so far, although I should be able to whip some up pretty fast.
But the biggest problem is my main food/booze-source, an underground farm that's outside of my fortress and requires my farmers to go out of the main entrance to reach it and would need a massive wall to block it if I were to connect it to my underground tunnels.

So a few questions:
Is it possible to construct a sort of pipe that channels water from a pool on the surface to some rooms underground by digging beneath the pool, without drowning the miner?
Like so (if seen from the side):
|+++| <-- water
--| |-----
--| |----- <--pipe
--| |-----
--|_;__ <--farm with floodgate
And with the new military system, the tips from the tutorial seem to be obsolete, I think I set my soldiers to train all year round, I set up a barracks with a small food store close to my entrance, but they don't spar there, they do "individual combat drills" and often run around not doing anything and their combat skills take ages to increase. I'm probably missing something but I haven't got a clue what... >_>