"I will walk and you will run."
Translation:jIyIt 'ej bIqet.
'ej conjoins sentences (or really any verbal clauses). It comes between the penultimate and final verb sentence being conjoined.
je conjoins nouns (or noun phrases). It comes after all the nouns being conjoined.
(There's also an adverbial je that comes after the verb is modifies; it means also. For example, Duj vIlegh je I also see the ship. This is identical in form to the noun conjunction je. Don't get them confused.)
pIj maSuvpu' batlh maSuvpu' 'ej maQapbejta'
In our many battles, we have fought with honor and achieved... victory!
Qu' buSHa'chugh SuvwI', batlhHa' vangchugh, qoj matlhHa'chugh, pagh ghaH SuvwI''e'.
If a warrior ignores duty, acts dishonorably, or is disloyal, he is nothing.
I make the assumption, quite justified I believe, that 'ej, qoj, and pagh all work the same way.
This is explained in the Tips and Notes.
After choosing a lesson unit, instead of clicking on Start, click on the little lightbulb icon next to it instead -- that will take you to the Tips and Notes. After reading them, you can then start learning that unit by choosing the Start button at the top of the Tips and Notes page.
Joining two nouns is explained in the Tips and Notes for the first unit, https://www.duolingo.com/skill/kl/Useful-phrases/tips-and-notes (section Joining nouns with and without "and"), and joining two sentences is explained in the Tips and Notes for the first unit on the second row, https://www.duolingo.com/skill/kl/Sentences-1/tips-and-notes (section Joining two sentences with "and").
If something is still unclear to you after reading the Tips and Notes, please ask specifically.
If you feel you have understood the difference, I suggest you try creating a couple of phrases or sentences here for practice. (For example, how would you say "Torg and Mara walked" or "Torg jumped and Mara ran"?)