Winning a prize from a bank

Q: I have recently opened a bank account and the bank has a scheme for all its customers where one account number will be chosen in a lucky draw... The account holder will receive some price money.

There is no payment required to be a part of this lucky draw.

My question is, if someone wins the prize money... Is it halaal to use this money?

The concept of taqdeer and the purpose of life

Q:

1. What is the concept of taqdeer and Allah knowing and deciding our taqdeer?

If dua can change taqdeer, then does Allah not know of the dua or is dua bad? But we are supposed to ask in dua.

I feel like when I make dua that many times it does get accepted and come through, but most of the time it later backfires and the same thing that I was given causes me more pain and suffering.

2. What is life's focus supposed to be and why should we do it? What is my personality supposed to be like as a Muslim?