A QJx rainbow flop is a really good flop for AK in position. You have the initiative of raising preflop, the face cards hit your percieved "range" and your hand has AAAKKKTTTT (10 outs) twice against
hands like 88,99,TT or Jx that are going to fold to your barrels.
Even if we don't improve we win here a lot.
If we bet as a semi-bluff we can get worse hands to peel (KT,9T, 8T, 89) and we can get hands with absolutely no plan (small/medium pairs +Jx) to float and then fold to our turn bets.
When we are up against squarely a queen, our hand still has reasonable
equity.
In the absolute worst case scenario (up against a set) because of a dry board texture we can execute pot control, and if we make the nuts (ten ball) we can play for stacks - great implied
odds.
The only problem with this flop is when your up against AQ,KQ, QJ, KJ type hands that have you reserve dominated. That is a serious problem, but it can largely be countered by the fact that we have position.
Also, how to continue is almost entirely dependent on your stack sizes. If your 100+ big blinds deep continuing would be mandatory, checking back would be a serious leak that I would anticipate from a bad weak/passive player.
you will learn how to better interpret board textures with practice.