I thought I'd provide a quick list of my fave software that I use all the time - some may find it useful! Many are paid - check out stuff like SetApp as that may have the app in it, and it's often far cheaper via there if it does.
BarTender
You can use this to tidy up your menu bar - really handy on a laptop with limited space.
HyperDock
Gives you great window management - similar to Windows. One of the areas I think MacOS is kinda lacking. If an application has multiple windows, you can hover over the icon in the dock and you get a preview of all the available windows.
DaisyDisk
It scans drives (both local and network drives) and gives a nice GUI of where disk space is being used. You can click down into each segment for more detailed info and you can use it to clear purgeable space as well.
AutoMounter
I love this app - it's ace. This is useful for those of us with more than one computer, or those who have a NAS and want to ensure that they always have a network link to their other devices. I've found that macOS isn't especially good at remembering what other computers you're connected to and doesn't seem to reconnect if the other device goes off line and then comes back. AutoMounter gets around that and does it in a clever way. You can set conditions so that it won't try and mount shares if the remote system isn't available and you can set custom mount points.
Carbon Copy Cloner
File sync/backup utility. Incredibly flexible and great performance too.
Downie
Really handy utility that allows you to download videos from websites and the like.
Better Touch Tool
Perhaps a more tech one - you can modify all kinds of behaviours from trackpads to shortcuts etc.
MacUpdater
Great app for keeping all your software up to date.
OverSight
Gives you an alert when your mic/webcam is in use.
PathFinder
Finder replacement - far more powerful.
AppCleaner
Removes apps - everything, not just the main app.
OnyX
Maintenance app for MacOS - be careful with this if you don't know what you're doing!
Alfred
Replacement for Spotlight - so, so powerful. I find trying to use a Mac without it frustrating as hell.
Countdown Timer Plus
Puts countdown timers on your desktop - really handy to remind you of events etc.
PDF to Word+
Does a decent job converting PDF files to Word.
iStat Menus
Great for the techies who want to see what their machine is doing.
Fantastical
This is my main calendar app and it is AMAZING.
I'll add others and links when I think of them. Stuff like Parallels/VMWare Fusion for virtualisation, Jump Desktop for RDP/VNC management,