I'll take a cut at trying to get you pointed in the right direction.
I. Encore has several meanings
In the skill 3.12 School 2, (this is units 34-36 in the new tree: 34.6 35.6 36.6), encore means again:
Tu lis encore ce livre.
You're reading the book again.
In 3.13 Food 2, (35.3 36.4 37.3), encore means still.
Il est encore en train de cuisiner ?
Is he still cooking?
In 5.14 Nightmare (70.8 71.9 72.8) we learn pas encore, or not yet.
In 6.16 Office 2 (90.4 91.3 92.5), encore plus or encore moins is even more or even less.
Aujourd'hui, je me suis levé encore plus tôt.
I got up even more early.
Ton bureau est encore moins propre que le sien.
Your office is even less cleaner than his.
This site must has some moderator-written documentation about encore and it's different meanings. I found out from the pros on the web so that's what I know. Someone here could come along and tell you, so you could wait for them if you don't like the videos & can't find the docs here.
Francais Authentique
French School TV
II. Adverb rules
Adverbs generally go after the conjugated verb. This means the auxiliary verb in passé composé & the modal in modal + inf constructions. Longer and less common adverbs, including locutions, comme after the verb. Not everything follows that rule. The exceptions are presented by Duo one by one in the lesson where the adverb is introduced.
Here's the videos where I got my stuff from.
Cours de français
Grammaire Française
La place de l'adverb
Learn French with Elsa
Place des adverbes
French School TV
french adverbs, where to put them.