Yep you are only paid for drills you attend. There are 4 periods per DWE. INDOC is pretty straightforward, just PowerPoints from each dept and a bunch of GMTs. Make sure you get urinalysis done and fill out a EPHA to get on the PHA and dental list for the next DWE.
You can go to INDOC in civilian clothes or uniform depending on when you get a cac and uniforms. It’ll be based on the NRC POM which is prob type IIIs. Make sure your name tapes are properly seen and you can blouse your boots etc. otherwise just go in business casual.