no worries, you are learning, and I see through the silhouette of your shoe a very good understanding of proportions. I understand as well your attitude of doing something new, instead of reworking what has been done before.
There are different ways to learn, either by revisiting whats done or taking feedback and jump to the next attempt. sketching, and rendering is only one part of the job, and since u are not supposed to get through technical drawing and design packs, prototype review, sometimes questionable marketing requests…then have fun.
I think u are talented, I think passion will drive u through different ways to draw and approach footwear (prospective etc…)
BUT keep something in mind, if this is the job U dream of, please try to get as soon as possible an internship in one of the major companies.
you will be exposed to the right people, experienced, the one u can learn from wether it is all about function, constructions, material specifications, processes etc…
don’t forget, the sketche becomes a product one day, this product must be tested and approved by the dealers and the final consumer.
keep challenging yourself, think 5 years ahead minimum, imagine and draw what doesn’t exist, forget Free, foamposite, jordan, air, shox, project yourself in the future as if you were a Nike designer already.
again, what makes u different or special, what kind of benefit u can bring to whatever company?? Why Should I hire or trust in you???
because you are a student, Have fun, no limits, dont be a half copy cat,
inspire us, inspire them.
all the best