The never have kids standing in line is over rated imo. Sometimes it has to be done. It shouldnt be all the time and the whole session but it has its place. Including making sure players are using proper form.
Here is a shooting drill that can work for U8 because it works a lot of different things
Split the teams into two teams of 4. In a square (different sizes depending on age), the players on blue are playing possession and trying to get X amt of passes strung together without the red player stealing it or having it go out of bounds. So its a 4v1 rondo possession. If the red defending player wins the ball or forces the ball out, they get to leave the square and run on to the goal for a shot. The coach is the one playing the ball. If Blue gets X amt of passes, they have one point. If red scores on the shot, they get 1. Make it a competition and they will get into it. With shooting being your main concern, and the kids being young, have the red team shoot anyway even if blue keeps possession for X passes.
If you have extra kids, you can increase the numbers, but 4V1 in the square works best imo