If you’re ready to test your skills using the subjunctive in Portuguese, I’ve got an Anki flashcard set for you. The set is mixed with examples of present, past, and future subjunctives. Mixed in are some common pitfalls where you might be tempted to use the subjunctive. Over 100 cards in total. Download here.
See this post for more exceptions on when NOT to use the subjunctive.
Again, this is meant as a review, so first learn the basic vocabulary and rules and use this set as a basis for keeping that knowledge.