How do you reclaim a section of your yard that has gotten overgrown

Cut it down with a weed eater, mower, or other cutting device.

You've got your work cut out for you !!!

Here's a cute little video that might help you inspired...

https://youtu.be/H6lY9lHX-z0

Cut out all plants that you do not want and then trim the others. If you have a lawn, raise the blades on your mower and cut it down and then cut again to a height of 3 inches.

If you're in a rush, spray Brush Killer in the area, but do not let it 'drift"!. Once weeds are dead, rototill if possible, adding soil amendments as needed. Put down Preen granules to kill new weeds. Plant established plants (seeds and young growth will not withstand Preen). Fertilize, mulch, and scatter more Preen granules atop mulch.