I’d pick one area to start. The example you gave that struck me was failure to arrive to meetings on time. This behavior not only wastes everybody’s time, it is a sign of disrespect to the other members of the team.
I might suggest a session with the team to dialog the question; “What are your suggestions for making our meetings more effective?” As the boss, I think you are entitled to add your suggestion and even mandate an action. I would point out how disrespectful being late for meetings is to the other members of the team as it can cause them to waste time waiting for late arrivals or repeating things that have already been covered. (If people are late because the meetings are badly planned, you should identify actions to fix that too.)
I have seen several organizations implement a fine for people who arrive late, maybe $5. (At executive levels, I have seen much higher fines, but the amount isn’t important.) The fines can go into a pot and after the pot reaches a certain amount it can be used for something special for the whole group – a pizza lunch, beers after work, donuts, etc. Either the problem will get fixed or your group will enjoy a lot of treats thanks to the tardy members.