Remotely clear memory, make space on mac,

I have a MacBook Air (13-inch, Early 2015) Processor 1.6 GHz Intel Core i5. Memory 8 GB 1600 MHz

It constantly says:
"Your disk is almost full" Save Space by optimising storage.

But I don't understand why the memory is full. Can I share you access to my mac and remotely you help me solve what is eating my memory? Clear it. And perhaps increase my memory size. Either on my cloud or on the laptop itself.

Many thanks

Danielle