In below picture, is ammeter AC or DC? Is there direction for connection with load in series? If so what if I connect in wrong direction?
It's a moving iron meter hence this symbol: -



Taken from here

Moving iron meters are used for DC AND AC so, the meter needle will only move in a clockwise direction irrespective of current polarity. If it used a magnet it would be polarized and with AC, the needle would barely move (because the needle would try and move clockwise and counter-clockwise at the AC frequency).

It's also worth noting that the symbol that looks like an upside-down "T" next to the moving iron symbol also has a meaning as does the 5 sided star with a 2 inside: -



Extra picture from here.