MacBook update
Been trying to update my MacBook. Says I needed more storage, 21GB. Bought 200GB of storage. Now saying I need 18GB more. Help.
MacBook Air 13″, macOS 10.14
Sounds like you purchased more iCloud space which has nothing to do with the space on your drive, In any case, see this article on how to clear space on your drive. Free up storage space on your Mac - Apple Support