The rule for carry on is the same for every commercial airline: one carry on like a suitcase or backpack that fits into the overhead bin, plus one personal item that fits underneath the seat and this could be a purse, laptop bag or a small backpack. If your laptop bag is too big to fit underneath the seat, it would be considered a carry on, and in this case you are having 2 carry on bags which is not allowed. Bottom line, it's the size that matters, doesn't matter what kind of bag we bring.
As long as your suitcase will follow the rule of the size of the carry on you should have no problem. Check with your airline they should have rules regarding this. Good luck!
Depends on the airline. Most airlines however allow a small suitcase to go on the overhead and a bag that can go under the seat. You can put your suitcase if it fits the dimensions (check on the airline website for that) and keep your laptop case under your seat if you choose to bring that instead of a backpack or purse.
