Addon creation:
https://www.esoui.com/forums/showthread.php?t=8413
https://wiki.esoui.com/New_to_lua%3F_GOTCHA
https://wiki.esoui.com/AddOn_Quick_Questions
https://wiki.esoui.com/SimpleNotebookTutorial/part1
Hope this helps to get started with lua and addons.
Creating the UI is XML, and it can get annoying yeah...
You'd need to check teh Wiki for tutorials about the XML parts, and especially about the "anchors" -< Controls will anchor to each other.
You kind of draw the UI by adding the controls to each other.
ZOs provides some templates (virtual controls) you can reuse.
Like Lists or backgrouns or frames.