Question: how do I save, read ,,,,,, 10 years later..

I searched the questions for an answer before posting and found that I had asked the question 10 years ago! I still do not understand although it appears every other Maple user does. Embarrassing!
 

I have done some time consuming computations in my worksheet and would like to save the results for further investigation. Let's say, for example, that I have a long list L of numbers, strings etc, and a very large Matrix A . I am working on a Mac running 10.12.6.
From reading the documentation many times I gather that I can create a file with the values of L and A. I might then be able to open another worksheet and read the values of L and A into that worksheet but I cannot figure out how to do that.

Here are some of the (unhelpful) error messages I get using toy examples:

after creating a text file by hand

> read "testZ";
Error, unable to read `testZ` 

or

read testn. txt;
Error, read must have a file name

ro

read "Users/awass/Desktop/testn";
Error, unable to read `Users/awass/Desktop/testn`
 

So, how do I write my info to a file? Must I somehow create the file before I save?
Where should that file be placed? Desktop? Folder?
How do I read from the file after I have saved.
Can I save both L and A to the same file? Do I need 2 commands?

I would appreciate some explicit toy examples. Many thanks.