You can take all 3 pills at once at any time of day. Or you can split them up.
With or without food is fine either way. Personally I take all supplements with food to avoid stomach upset from pills rattling around in an empty stomach.
DHA does not have a tolerable upper limit (like Iron or Calcium). So you can do more than 3 softgels if you want. I wouldn't go crazy and just take handfuls of them, but it's not a big deal if you take a few extras. Personally I take 6 a day, 2 at each meal.
If you start taking more than 10 softgels a day, read this paper to determine upper limit safety:
https://efsa.onlinelibrary.wiley.com/doi/epdf/10.2903/j.efsa.2012.2815
Also, try this. Chew the softgels. It's kinda fun.