Obviously, colleges and universities offer Marketing certifications and diplomas but even after that, graduates should continue their knowledge and education since the marketing world is constantly advancing. Marketing is a very large department, so college and university can only teach so much.
Hubspot offers free training to further your knowledge and abilities to anyone interested. There are courses and certifications.
If you have a website and want to optimize it, Google Analytics Academy is a great learning tool. Skillshop is a great learning tool as well.
You can access some free tools and resources as well to help you grow. Just start doing it AUTHENTICALLY and your data will tell you what is working and what isn’t.