Each team has a number of riders, of whom only a couple will have a decent chance to win the race - the rest are there either with specialist cycling skills, or to provide maximum support to the potential winners. So it can be a tactical race between the teams.
There are different colour jumpers that are awarded daily to riders who meet certain criteria e.g. yellow jersey for the overall course leader (i.e. the person who has completed the course so far in the shortest time), the green jersey is worn by the best sprinter and time trialist, polka dot is the leader in the mountains, and while for best young rider.
And it's all in French; we had the Tour de France here in Yorkshire a few years ago (it can start in a country which is not France), and we still have a race every year which we now call the Tour de Yorkshire