Thank you for your post.
You're right. The vocabulary you need to learn are the basic ones, and relating kanji reading are also the common readings.
So as far as you know know the basic reading of the kanji, including those relates to the vocabulary, you'll be fine.
For example, the kanji 長, If you can see the screenshot below;
The pointed reading, 'osa' is one of the minor readings so that you don't need to learn that.
Hope this helps,