I’m a beginner and looking for slicer advice

So, I just set up my first 3D printer and did a test print of a square that’s preinstalled in the printer. It’s a FlashForge Adventurer 5m.

There’s something on thingiverse that I want to print, but I’m having trouble finding a good slicer.

My laptop is out of date and doesn’t get any more updates (it’s on iOS 10.11.6) so any slicers I download there don’t work because they need iOS 10.13 or newer. Maybe there’s a place I can download older versions of the programs? Idk

That leaves my phone and my iPad. Issue there is every app I look at for slicing has a subscription for it to work properly.

Any advice is appreciated.

Thank you in advance