Can I be able to transfer to a USA university or college from a Nigerian polytechnic

Answered

It will probably depend on what types of schools you are hoping to transfer to. It can be difficult to transfer as an international student but by no means is it impossible.

I'd recommend checking out the schools you are interested in applying at to make sure that you're meeting their requirements to transfer first. If you don't your first step will be to make sure you work on whatever requirements you are missing and then apply. If you have questions on certain requirements, how to meet them, cost of attending, etc. you will need to reach out to the school so they can answer your specific questions.

Most application deadlines have already passed. Some schools have rolling admissions so you could apply to those now. If none of the schools you are interested in offer rolling admissions then you'll need to wait for the next application cycle. That can be a good time to research and work on your application and essays. Those take a ton of time and effort so you'll want to start them as early as possible.