You can get your card symbols via Insert > Symbols > Symbol > Font > Scroll to Symbol.
Locate the required symbols and either d/click to insert, or select > Insert.

Alternatively, you can press the Numlock Key, then press the Alt + 3 keys for a Heart, the Alt + 4 keys for a Diamond, the Alt + 5 keys for a Club and the Alt + 6 keys for a Spade.
Note the symbols are are little different when using the keyboard method.