You will find plenty of sources for Q-codes on the Internet. When consulting listings of Q-codes keep in mind that some codes tend to have a different meaning in ham radio.
Most Q-codes can also be used as questions, like QRK? = How do you read me? This is anwereed by QRK5 (I read you perfectly well) or e.g. QRK2 (I copy you partially) or QRK1 (I do not copy at all). QSL usually refers to qsl cards, a qso is just a contact between ham radio stations, qrl refers to work, qrl? usally askes whether or not a frequency is in use. Some q-codes such as QRK should be used with a subsequent number describing the strength of the phenomenon in a scale from 1 to 5 where 5 is always good reception while 1 describes a very bad hindrance. In ham radio practice the number after QRM, QRN, QSB is often omitted.