As far as I can discern there is not a helpful memorization pattern to them.
Instead I have opted for focused practice with flashcard software.
If you use Tinycards try either my decks - I made 6, one for each subject: https://tiny.cards/users/SporadicAspirant or Michael Lubetsky's deck: https://tiny.cards/decks/6fFfF6KM/duolingo-klingon-verb-prefixes
(Regarding my own, I'm still learning these, but believe them to be accurate.)
je is used at the end of a list of nouns and 'ej is used between sentences. So no, you wouldn't use je like you have shown. Well, not to translate what you are trying to say, there, anyway. I'll give you a preview ahead that it can be added after a verb to mean "also". So Suqet SuSup je would mean, "You run. You also jump." It's very close to the same thing, but slightly different.
A fairly good explanation is given in the Tips & Notes. If you have not been reading the Tips & Notes, I would like to ask that you review those so we don’t have to continuously repeat the information that we have explained there. If you have read them and still have a question, please be specific in your question so we can figure out where the confusion is.
If you are doing the course on iOS or Android, you cannot currently access the Tips & Notes through the app. To access the Tips & Notes, you will have to access the course using a web browser at https://www.duolingo.com/, either from your mobile device or from a computer. When you click on a Skill, it will expand to reveal a Start button and a light bulb.
If you click on the light bulb it will reveal the Tips & Notes and give you a detailed explanation of the grammar that is introduced in that Skill. If you have questions after reading the Tips & Notes for the previous and current Skills, then please return to the forum to ask your question, explaining what you didn’t understand or what seems contradictory to you.