When you try to OPEN WHAT?
are you opening software?
or are you talkign about physically OPENING the laptop lid, to see the screen?
If you run out of memory (also called RAM) and you also run out of hard drive space, you need to take action.
Start erasing stuff.....that you dont need or use.....or MOVE it off the drive to a diff drive or to the cloud.
Theres not much you can do for the RAM though, except install MORE RAM.
but that requires opening the computer and replaceing the RAM board sticks.
its easy, for even a non tehcnical person, the trick is making sure you have the correct ones to upgrade with.
But i would suggest you do a hard drive clean up......delet software you dont use anymore......and MOVE yoru files to a diff drive....maybe purchase an external hard drive you can connect to the compuetr.