As @phuzi said in the comments you can use double click to select the word or double click and drag to select word to word (it will snap on the last character of each word). If you triple-click on a line or click on line num, it will select the whole line (with the invisible character at last ‘\n’).
If you press CTRL + D it will select the word where the cursor is. Also if there are multiple instance of same word you can select them all one after another using CTRL + D.