Doing hormones on your own is not recommended. They are very dangerous, and can easily get you killed. Also, it would not be a good scenario when your parents found out. I can see your rush, but transition is a life-changing, dangerous process. You can't just rush into it, or you may damage yourself permanently.
The first thing to do is to become as self-sufficient as possible. You don't want to be relying on your parents, because if it turns out they don't approve, they can cause a lot of complications if you are still dependent on them. Also, find a good therapist if you can. You sound like you are still confused and trying to work things out. If you want to take hormones, that is something that you should be doing with a clear head and firm decision. Transition is like walking over a rickety bridge across a bottomless chasm. There's no reason to do it blindfolded.
One thing is for certain, if anything can help you it is money. Money is a hard limiter for TG folk. Hell, money is difficult for anybody. Find a job or some means of income, and save up as much as you can.
1:- do they help in growing boobs and when can we see the change is happening and how long is that going to take
Growth is likely, over time. But it takes a while, and it is dependent on genetics and health.
2:- does it help in gaing curves and prpreshapes of hips and all as iam verp slim but wann a have curves like girls
It can help somewhat. Again, it is very individualized. However, if you are slim, you are less likely to experience noticeable change, because body definition is defined by muscle and fat, and slim people are typically lacking in both.
3:-do they help in improving complexion and make skin soft becaus as most of indians iam not very fair
Often times, yes. Complexion is also greatly affected by diet.
4:-do they going to change my face structure like more towards female side
Not necessarily. It may change slightly, such as fat deposits, but bone structure is extremely unlikely to change. Hormones typically won't do anything for a big nose or hard jaw.
5:-are they going to effect my body hair and if yes how are they going to fall or what
Your best bet here is shaving. Hormones may or may not have a big affect on body hair, it depends on the individual.
6:-its better to take injectible harmones or pills
I'd say that really depends on the circumstances.