"the drive is still in the MacBook although it's easy enough to get it out. It will boot but the issue is this. The Mac wasn't working well and so it was taken to a local computer shop who set it back to factory settings without backing it up, now all the photos are missing. I have some recovery software that can find deleted items and recover them but the drive that it finds them on should be set as a slave drive first and connected to another computer that is running the recovery software, then they should be recovered to a different drive."
One never never NEVER hands one's Mac to another for "repair" unless the internal drive has been properly backed up first.
Go forth from this day and learn -- a sadder but now wiser man.
Having said that, I offer you a pathway forward.
Are you willing to walk it?
Here's what to do:
FIRST -- do not boot and run the Macbook on its own. If you do, there's a high chance that the "old data" will be over-written, and thus destroyed and UN-recoverable. The data may already be un-recoverable. We don't know that yet.
NEXT -- buy an EXTERNAL drive of some sort. It can be SSD or HDD. It should be large enough to hold the contents of the drive that is inside the Macbook. SSD would be best.
NOW:
a. Connect the external drive to the Macbook
b. Boot the Macbook to INTERNET RECOVERY:
Command-OPTION-R
You'll need your wifi password, and internet recovery takes a while to load.
BE PATIENT.
c. When the internet utilities appear, choose Disk Utility.
d. Go to the "view" menu and choose "show all devices", if that choice is there. If it IS NOT there, don't worry about it.
e. You should now see (in the list on the left) your EXTERNAL drive. Click on it to select it, then click the erase button. Choose Mac OS extended with journaling enabled, GUID partition format.
WARNING! DO NOT ERASE THE INTERNAL DRIVE!
f. Once the internal drive is erased, you can quit Disk Utility and open the OS installer.
g. Begin "clicking through" the OS installer. IMPORTANT: when it asks WHERE you want to install, "aim it" at the EXTERNAL drive. We are going to put a copy of the OS there. So... let the installer do its thing.
h. This will involve one or more reboots, the screen going black for a while, and will take some time. BE PATIENT.
i. When done, you should see the initial setup screen ("choose your language"). So do a VERY SIMPLE setup, just create a username and password. DON'T BOTHER with iCloud, email, etc. yet.
OK, if you got this far, you are now booted and running FROM THE EXTERNAL DRIVE. This means you can examine the internal drive WITHOUT "TOUCHING IT" and without damaging the data on it.
What I would suggest next:
Download ProSoft's "Data Rescue" app. It will scan the drive and give you an idea of what is "recoverable" -- IF anything is recoverable on it. DON'T PAY for it until you have an idea that something can be recovered.
Or... use the data recovery app you have now (you didn't tell us which one that is).
If there is data that can be recovered, you can save it to the "empty portion" of the external drive. Once you have saved "all that you can get", you can then boot back to the internal drive, and begin rebuilding things.
A word of advice:
It can take A LONG TIME to recover data that has been erased this way.
I'm talking MONTHS, or even YEARS.
It can be done, but you will probably lose file names and folder hierarchies.
Sometimes things go easier.
OK, that's my "path forward".
See where "not backing up" has brought you?
