This sounds like a larger problem. Unless they're trying to get you to invest it or something "responsible," it seems like a red flag that someone as interested in computing as you appear to be would have parents stifling their learning.

On a more useful note, there are some good courses available on Coursera:

https://www.coursera.org/courses?query=algorithms&languages=...

Both the Stanford and Princeton intro courses there don't appear to require nonfree texts.

Also, I wouldn't worry about a course being "old." Algorithms don't really go out of style, outside of some advanced topics like concurrency and architecture-specific design. Algorithm texts from the last century (or perhaps even earlier, if you look at number theory work by ancient mathematicians) are totally useful and relevant today.