Generally (it can vary by airline and operation) you’re required to show up about an hour before departure time (aka “go time”). There’s also some time after to shutdown, debrief whatever. BUT, this is the airline industry and unless you’ve never been to an airport you’re probably aware of the dreaded “DELAY”. Delays are caused by weather, maintenance, passenger issues, airport congestion and just about anything else you can think of. depending on where you’re based it could be a relatively minor concern (I’m based in HNL where it’s beautiful ALL the time) or a concern EVERY DAY (say IAH in the summer, ORD or EWR in the winter). These delays can add minutes, hours, even days to your schedule. Back when I was in EWR I was once supposed to do a very easy YOW turn, well Hurricane Sandy hit when we got to YOW, my 4hr trip turned into 4 days.
Bottomline is if there’s something you can do on your laptop whenever you have the time you’ll be fine but if it’s something that requires any kind of set schedule or appts you will not. At least for a while.