Hi
Yes, never defrag your SSD they don't need it, but leave some free space as Neemobeer said.
If possible don't put anything other then your Windows install on your SSD drive.
Use a conventional drive for programs and storage.
The file tab is as shown in the image below inside the red box...
I run this on each of my drives once or twice a week.
Sometimes when I'm doing video editing and the files are really big, I use this to defrag a specific file.
You would be surprised how much difference it can make.
I've actually had video creation fail, until I defragment the file then it goes through.
Mike
PS, I just noticed that Ron answered the question about where the file tab is. LOL