What kind of products are you selling? Do you have concerns about liability? If not, I’d stick with a sole proprietor for now.
I sell on Amazon as a side hustle and have kept with a sole proprietorship, similar income to what you projecting. For me it wasn’t worth the hassle and cost of setting up the LLC, filing those tax returns etc. I just report the 1099 income on my personal return and set up a SEP IRA to take advantage of that deduction.
However I do not sell any food, supplements, vitamins, etc. because I don’t want the liability risk in the event someone became ill or injured from a product I sell.