If I knew this guy was a set miner, I could find a fold here
If I knew this guy was a tard, I could shove here
but he was completely new to the table so I don't know wtf to do

Full Tilt No-Limit Hold'em, $0.50 BB (8 handed) - Full-Tilt Converter Tool from FlopTurnRiver.com

SB ($50.25)
UTG ($50)
Hero (UTG+1) ($50.75)
MP2 ($59.60)
CO ($76.50)
Button ($77.30)

Preflop: Hero is UTG+1 with K, A
Hero raises to $1.75, 3 folds, SB calls $1.50, 1 fold

Flop: ($4) 7, 10, A (3 players)
SB checks, Hero bets $4, SB raises to $12.75, Hero?