For OP, go for what others suggested above that are FREE. Avoid those paid courses because some of them, or most, are just the same as what you can access in free courses, especially on YouTube videos, if you want to learn from videos, or else go for some written articles, just like what was shared above.
Some of all these paid courses, although they are paid for they will never reveal to you the complete details that you should be aware of because the writers always hope to release volume two just to ensure that they have people who will pay for more courses. If you want to learn about perpetual trading or any other trading, there are numerous resources online where you can piece in information from side to side and get a good trading strategy that you'd been able to form accumulating different materials in the Internet to get pattern.