When going outside, I always take my cell phone, purse and a bottle of water.
Correct: When going outside, I always have my cell phone, purse and a bottle of water with me.
We use "take" when we take things to the place we are going to. We take them from the place where we are to another place. Take is used in relation to a starting point. In here, you do not take your things to another place you just have it with you.
Cell phone is important to me because I don't remember phone numbers of my friends and colleagues.
Correct: Cell phone is important to me because I can't remember the phone numbers of my friends and colleagues.
We use can't
Purse is import to me because it has a lot of cards and cupons.
Correct: Purse is important to me because it has a lot of cards and coupons.
Be careful with your spelling.
Finally, a bottle of water is important to me because I don't like drinking water.
Correct: Finally, a bottle of water is important to me because I don't like drinking tap water.
When I am thirsty, I drink water. Correct