It is weeks (even months) overdue for a cut and I am kicking myself.
However I need to be practical. If we are indoors for weeks I need to trim it.
I have never trimmed hair in my life 
I will get decent scissors (reccs??)
So her hair is long with long layers and I just
Want to take off the damaged ends, nothing really off the length if that makes sense.
When I get my own similar hair cut I notice the hair stylist cuts kind of INTO The ends of my Long layers at a kind of 45 degree angle? Some cutting just ‘straight’ too but then she randomly cuts ‘in’ with the scissors at a slight angle so that the ends of what she’s holding are then a little uneven?
Does that make sense??
She’s a great hsidrssser so I’m assuming her technique is a good one!!
Are there any online (easy, quick, idiot-proof) tutorials I could seek out?
Huge thanks!!! We can’t go many more weeks with untrimmed hair; she’s starting to look like a haystack!