need information on serengeti national park.?

i am a nature lover my dream is to visit serengeti national park once in life.in next six months i am planning to visit the park. As i am not much aware of african countries as well as serengeti national park i need some vital information for there.
1 ) i am residing in india so from india where i must land in kenya or in tanzania ? if in kenya which airport and if Tanzania, which airport ? 2 ) is it one national park of there are some different parts of this park ?
3) as i will be alone is it safe to be there alone ?
4 ) how much and how they manage guided safari ?
5 ) how about hotels there ?
6 ) how long i must plan to visit complete park ?
7 ) which season or month are the best time to visit serengeti specially for good photography?
8 ) what about the language do they understand english well ?
9 ) what about visa requirements ?
if there are any tour operator name.

just come right now, this is the migration time.