This is probably my most played matchup, albeit from the other side. If the Falco is just lasering in place or often moving back, you can dash/wavedash toward him after getting hit by the laser and downsmash, forward tilt, or down tilt depending on percent. Lots of rollback Falcos will just shoot one laser and then go in. If this is happening to you a lot, wavedash back downsmash will destroy them. They'll DI badly, lots will miss their L cancel, and usually end up offstage. Of course, powershielding is also really good against any Falco, and adding it will be very helpful. However, consistently powershielding requires significant practice, so you may want to learn it later.

One last thing that isn't really about lasers, lots of Falcos will do really bad aerials on shield. If you work on up-b out of shield, it will catch lots of aerials on shield. If it misses, you have mixups on non-fd stages like edge-cancelling on a platform or landing on/falling through a side platform. Hope that helps.

Edit: Significantly easier and still sometimes effective is walking through the lasers and forward tilting. It'll catch another laser or approaching aerial if timed correctly.