You should have received training from your stake clerk (General Handbook, 33.4.2). Any questions you have should be directed to him first. He should be familiar with both general and local instructions related to your calling. Additional resources include appropriate sections of the General Handbook, Help Center articles, the Tech Wiki, and of course, as you have found, here in the Tech Forum for specific questions and discussions on current topics of interest.
Back to the question of the Other category. If you have not done so yet, read the Help Center article The “Other” Category. Some of The General Handbook references in that article are not up to date and do not reflect the more recent changes. But with a little searching you can find and get to the correct reference.
All unit finance information, reports, and actions have been moved to Leader and Clerk Resources (LCR). I have not checked recently but when some actions are attempted in MLS most, if not all, actions will redirect to LCR Finance.
Managing the unit specific categories of the Other:Authorized Member-Financed Activities (AMFA) is done in LCR > Finance > Budget > Manage Categories. The instructions for managing the funds of the Other:AMFA categories is provided in the The “Other” Category article and in the General Handbook. Sections 34.5 and 20.6 are two sections that will get you started.
Topics discussing the management of Other:AMFA funds and specific situations can be found in the Tech Forum section Local Unit Finance. This thread is found in that forum section.