Start small!
A simple infantry firefight with no artillery or vehicles.
Maybe try re-creating the encounter from Book One pp13-16.
Remember always that the key thing in Striker is that you control the High Initiative/Elite figures directly - everyone else is, in effect, an NPC. So make your officers and senior NCOs Elites. Then use them to either LEAD or ORDER everyone else in your force.
Become very familiar with Rule 10: Command. Understand who can LEAD and who can issue ORDERs and the mechanics of doing each. Understand who responds to ORDERs, and who must be LED to do anything worthwhile. Understand that "troops who are being led by a high initiative officer/NCO may perform any action the player wishes".
Grasp the morale rules. Appreciate that, in Striker, receiving enemy fire does not cause morale checks on a fireteam stand. Rather, in this ruleset, only visible casualties nearby or visible enemy in close proximity force morale checks.
Note that Spotting is almost a game within a game in this ruleset. Spotting is not deterministic (i.e. at a certain distance a target is always spotted), rather it is probabilistic and requires a dice throw. Note that you roll 2D6 once for each target you're trying to spot, regardless of how many of your units can see it. Appreciate that a target spotted in a fire phase may not be fired at in that same fire phase, and can only be spotted if it has fired. Read carefully what counts as Concealment and when you may be Hidden in this ruleset - noting the differences for infantry compared with vehicles.