We will only need to get around Paris on May 15, the day we arrive, and the following day, the 16th. The next day we are off to Giverny by train. Then for May 18 and 19 we need to get around again. We prefer bus to Metro. So do we each get a carnet or is there some other practical way of buying tickets for transport? Thanks.
A carnet of Ticket t+ would likely be best unless you plan on taking more than four rides per day. Then you would benefit from getting a Mobilis day ticket.
If you decide to go with a carnet / booklet of 10 tickets, you can share these Paris transport tickets amongst your party. Not everyone needs their own booklet.