The Global Mission scenario has a giant plantary defense gun going off at the start of turn three so everyone had to seek cover by the end of turn two.
Between that need and the sheer amounts of firepower the Aquilon were laying down as they descended this building had four Necrons holed up inside it.
I had my Tempestor bark a command to boost a trooper and run over to fight through the doorway. She lopped up the first Despotek and a charge attempt by another Necron ended with a "Ran into my Power Sword ten times" scenario.
From an ease perspective the 40k start sets make it simple to test the rules out with minimal commitment: https://www.warhammer.com/en-US/shop/warhammer-40000/start-here
All sold out on their site, but available at plenty of other places.
They just announced a similar Starter Set for Kill Team that looks like a good way to test out this game: https://www.warhammer-community.com/en-gb/articles/B3EtzIYC/kill-team-starter-set-space-marines-vs-plague-marines/
If your ready to pick a faction and get painting/playing I think the 40k Combat Patrol format might be one of the easier options to pick up and play. No need to make an army list, the core roles are free, only needing you worry about knowing the stats/abilities for 4 or 5 squads. https://www.warhammer-community.com/en-gb/articles/7VlmRolQ/download-the-new-warhammer-40000-rules-for-free-right-here/
Kill Team is less models (7-10 per side), but they are often almost all unique and it really needs you to get some terrain set up to play right. But there are "lite" rules available for free right now that make it easier to try out: https://www.warhammer-community.com/en-gb/downloads/kill-team/