Personally, I would not recommend colleges as things in SEO change too quick for any course work to keep up to date. For example, a huge update was done this month to googles core algorithm which has got many so-called experts scratching their heads. No official name for this update but I am currently calling it the pandemic update.
As for learning material and trying to decide a route forward, I would watch a few videos on youtube (a bit hit or miss) but once you have a general idea I would nip onto https://www.udemy.com/ and find a course that suits you there. They have sales on all the time so wait for one of them before buying a course. They can be as little as $5 but most of the time around $10. Be sure to watch the intro as a lot of lecturers can have strong accents and hard to understand. So find one that has good recording facilities and native speaking. There are many based in the USA so I would imagine you will be spoilt for choice.
I would, however, avoid ones aimed directly as SEO, as with the college courses, they go out of date way to quick. Learning how to do PPC, marketing your site, etc are mostly evergreen so look within that niche.