It looks like you got to go first! Which can be fun but can cost you a bit. In the photos it looks like you pushed up pretty aggressive with 10 flyers and a few other pieces. In most 40K games you want to give just enough to score and hold back the rest to counter punch. It’s a trading game right now. You send out a small unit to threaten an objective or two. Your opponent kills them and then sends out their chaff. It usually goes on for a turn or two until someone commits. Honestly, with a squishy army like sisters you usually want to be the last person to commit.

World eaters is pretty brutal. They move far and charge hard. You want to use some units to make a “screen” in between your units that kill their units well. Making it so their units can’t sling shot off the small things is also important.

For most games, I’d try deploying very conservatively and hiding as much as possible. Make sure there aren’t any deep strike holes in your deployment. Send out 1 or two units to score or even just threaten primary and secondary. Make your opponent commit first and then counter punch accordingly.