Place your cursor at the start of the address in the address bar of your browser it should change to the little straight bar you see in word processors when working with text. Click and drag the cursor across the address or, in some browsers simply double click on the adress. With the addresss now highlighted "copy" the address using the control-c or copy command from the menu. The address is now in your computers virtual clipboard and can be pasted, using control-v or paste command, into an e-mail, letter of anywhere you want too.
Some e-mail programs also have the facility to import addresses from your internet browser. Look in the menu's for an "insert" option which may, in addition to inserting pictures etc, allow you to inert hyperlinks from your browser which should be left open in the background.
There are several other ways to achieve what you want but hopefully either of the above methods will work for you and make things easier.
Regards
Andy80F