New 3D print user needs help

I recently got a Ender 3 and have printed several things by downloading STL files from the net and running them though the Creality Slicer software. I recently found a very simple design but I only need to print a portion of it and would like to not waste my materials by printing the whole thing only to throw half of it away.I downloaded and TRIED to use Blender and FreeCAD to edit the file and have struggled extremely. I know its a simple task yet for some reason my old brain cant seem to understand what to do.If anyone could help me edit the file i would be greatful. I have attached the .stl file also. I am basically wanting to lop of everything to the right of red line on the posted image.Thank you for any help in advance

I'm not very good with this stuff either, but I think an easier program I've heard of to do stuff like this is called Mesh mixer: https://meshmixer.com/

See if there is anything in the slicer software that lets you split or cut an stl file.

Prusa slicer shown which seems to be an excellent slicer

Meshmixer is truly an easy approach, but not if one is unfamiliar with it. YouTube is handy to find plane cut Meshmixer, but it's easier for me to chop it as requested than to parse out comprehensive instructions. If the clipping is done at the wrong location, let me know.

Hello i use tinkercad it is a website just google tinkercad and import your stl then use square hole of the right and possession it correctly and group the object in the top right
p.s. you will have to create a account and you can also send the file to me and i can do it for you if you want.
Have a great day.
:)

Thank you so much. I have just started a print on it and will let you know how it worked out.

I am going to test out TinkerCAD and MeshMixer as you have suggested. Thank you so much for your help. Ill keep you posted

Ok great that it work out