The #Linux Desktop has some great #FOSS #DesktopSearch apps I use almost daily

- fsearch: blazing fast searching for filenames with a simple GUI, I use it for local filesystem searches (regex + wildcard search is supported)
https://github.com/cboxdoerfer/fsearch

- recoll: full text index tool with advanced GUI that really lets you deepdive into your files. I used it to query my (Cloud Synced) Document locations
https://www.lesbonscomptes.com/recoll/pages/index-recoll.html

Both apps should be provided by your OS package manager #TryBeforeYouDie