Sorry to say but, it is very unlikely that you'll succeed at this level of competition. If the team is very small, you might get a chance to swim in some meets.
As far as practices are concerned, the team should be practicing at least once per day swimming around 4 miles. Good teams will practice twice a day and swim around 6 miles per day.
I'm not saying what you want to do is impossible ... just a real tough thing to do.
Good luck.