Tour is a French equivalent of the Scottish Gaelic word tùr. The pronunciation of the feminine singular noun -- which translates literally into English as "tower" -- will be "toor" in French.
If you finish in the top 20 in Q-school, you will earn a category 12 playing card which means you will play in all full field events. If you finish 21-45 you will earn a tour card but it will be category 17 which means you will probably not get into many events and will be playing mostly on the Symetra Tour.