College acceptance letter?

I have 2 questions first i applied to a college and they sent me a later 2 weeks later saying we are happy to anounce your acceptence allegany college of maryland for 8/8/12 which is next year when i finish my senior year. so what should i do now should i call the school now or wait until im well into my senior year to call them. Then it said to final the it acceptence i have to give them my final high school transcripts and take a placemant test but how do i take the placement test. The college is far from were i live so do i have to travel all the way to the college to take the test or can i wait until i get to the college before classes start