[bitfolk] Any Oracle DBAs on the list?

Long story short, are there any "genuine Oracle DB admins" on the list? Many, many (many!) years ago, I "inherited" DB admining of SQL Server, Postgres and Oracle for my employer. SQL Server and Postgres are no problem at all, and thanks to a previous staff member that actually knew Oracle I've been able to get by in OraDB - he gave me a simple "cheatsheet" that worked until 12c released and multi-tenancy became a thing, and I've been able to tweak said cheatsheet for multi-tenancy for our very simple DB usage. But... I've now been tasked with adding an additional user to an Oracle schema/tablespace/database, and I can't for the life of me get it to "just work" like it does in SQL Server and Postgres. Happy to take this off-list at the earliest opportunity. Kind regards Murray Crane