The criteria for technical correctness are listed here: What are the criteria to decide whether a photo is "technically correct" or not?What are the criteria to decide whether a photo is "technically correct" or not?
For me there are more important considerations though. I'd ask myself if "photography is a creative entertainment or source of income for me?". Once you start selling your images, you'll optimize your images for selling and thus limiting your creative freedom that you have as an amateur.