im a guy who needs some answeres

As far as the straightening, you would fare better asking this question on the "straight talk" forum, where people straighten a lot and are familiar with these products.  Here on the long hair forum, many don't straighten because it is so damaging for those who want long hair.

As far as what people tell you, just because your hair is curly doesn't mean it won't look good long...I've seen some curly haired people with the GREATEST heads of long hair.  You can always do something about frizz too to improve it, like adding a little jojoba oil (a drop or two, very little) to your hair to tame the frizzies.  Curly haired people often use a different regime on their hair to keep it looking good as well (such as not brushing it after its dry, not blow drying, etc.). When people tell you how you should wear your hair, they often have ulterior motives or ideas of what they think is acceptable that color their opinions.  Wear your hair how YOU want it, its yours, not theirs.