how do I make my hair soft and not frizzy
Incorrect. The more you straighten your hair the more damaged and frizzy it will get.
You need a better conditioner.
Try "reconstructive" (or "colour restore" or "anti sponge/frizz" these are all codes for the highest level of moisturizing) conditioner by Tresemme. Condition your hair in the shower, let it sit for 3 minutes with the conditioner in, and rinse thoroughly. Then when your shower is done put a TINY drop (pea size or smaller, depending on how much hair you have) of the conditioner in your wet hands, rub your hands together, and run the conditioner through your wet hair from the tips to the roots.
You could also use a cream for styling (I use "Curl Hydration" also by tresemme). Stay away from blow dryers and straighteners.
get a straightner -.-