Whether or not someone will pay you for your work or how much they'll pay is between you and them. Many awesome photos have been given away; many junk photos sold for premiums. Those are business and marketing decisions and, if you really want to ask that question, please do so.
But, I'm getting the feeling that you're looking more for photo advice over business advice.
The photo that you uploaded has some pros and cons. As a portrait, there is nothing interesting about the subject. She is turned away from us (not always a bad thing) but we are given nothing about her. This is generic brown hair girl #1 - and very few people will pay you for an image of themselves that doesn't portray anything about themselves.
The framing is a bit wide with nothing drawing the eye to the subject. The road and clouds look like they could have made for some cool leading lines had you changed your angle and subject distance.
Your exposure and use of fill flash is pretty good here. If you've got a good handle on mixed lighting, you're already technically one step ahead of many people. I would copy some of the activities on https://strobist.blogspot.com to sharpen your skills further.
It may just be the image size, but the subject looks out of focus. Whether you are actually out of focus or just not in the sweet spot for your lens and aperture combo, it doesn't much matter to the buyer. OOF is OOF and it's worth $0.00.
Google "Environmental Portraits" to start to get some ideas for framing, composing, and lighting these types of portraits.
If I were the subject, I would not pay you for this photo. But, that's me. Your subject could love it and give you cash for it - you'll find a great deal of variance in expectations across the market.
As a portrait, it is well exposed and your mixing of fill and artificial is a good call, one that you should keep practicing. But, your composition could be better. A portrait should always be about the subject; here, she's only getting in the way of an interesting sky.