Open Settings from the rail or your profile menu. Its sections are grouped under Account, Maps, AI & integrations, and Organization; the four below are the ones every user touches. Security is on Security and Sessions, and address search on Search and Geocoding Providers.
Profile
Account → Profile holds your details. Keep them current — this is how colleagues recognize you in member lists and sharing dialogs.
Appearance
Account → Appearance covers light or dark Mode, your Theme color, your interface language, your time zone, and whether the left rail collapses until you need it.
Changing the language changes the Tamaat interface. Your own data and layer names stay as you wrote them.
A Preview updates as you go, so you can see a theme before you commit to it.
Map display
Maps → Map display covers where address search sits, how coordinates are formatted, and whether the toolbar floats over the canvas (and which tools it carries).
Basemaps
Maps → Basemaps sets what's drawn behind your layers, both in the map builder and in maps you publish.