I agree RST is a good investment and more importantly, apply things you learnt.
Craft your own path.
Test Automation University Courses are good.Simple to follow for automation
MOT for guidance on topics.Lot of blogs and articles to read.
BBST courses by Dr Cem Kaner
Books
Testing Computer Software
Perfect Software and other illusions
Lessons Learned in Software Testing
General Systems by Jerry Weinberg
Exploring Requirements Part1 and 2
Agile Testing Condensed Lisa Crispin and Janet Gregory.
Blogs
satisfice.com and developsense.com primarily
Communities
MOT and RST slack