OmniDiskSweeper to identify what items are taking up the most disk space.
Even so, those aren't mandatory. 'Cleaning' apps will do more damage than good; that applies to both Windows and Mac. If you don't know what these apps are doing (which you don't, as on the front end they just give you basic flashing lights and a few vague comments), then you shouldn't be using them.
I've used AppCleaner, MalwareBytes, OmniDiskSweeper, and Onyx with good luck for quite a while (Onyx I've used going back to Snow Leopard). The only other cleaning/repair/utility Apps I use which are paid is iStatMenus (which provides the status of numerous system functions), DriveDX (which checks for failing hard drives [and some flash drives if they have SSD controllers in them]), and Disk Warrior (which repairs damaged directories that macOS itself is unable to repair - but an APFS version is yet to be released.)