First, noon online, or even in person is going to ever be able to intelligently tell you just how much is enough for you.
That said, codeine is very safe as long as it is confined to oral usage (never inject), because of a metabolic celing of roughly 600 mgs. on average.
A recreational dosage is usually in the aerea of 4 to 500 mgs., but if you are opiatenaive, meaning not really used it, then start small and wait 30 minutes, and increase as needed. Also, be very careful if taking codeine preperations as opposed to codeine by itself. In other words, if taking Codeine/APAP or
Paracetemol., know that the additive can kill your liver quickly. There are wys to remove almost all the additive, and it is very simple, look for threads on "Cold Water Extraction AKA CWE."
Also, a very uncomfortable side effect is a great amount of histamine release. If possible, take promethazine, which aside from working wonders on histamines, and also adding to the sedation associatedwith codeine, boosts the natural conversion inside your body of codeine into morphine.
Psychoactively you will be getting "high" not from codeine butfrom morphine its primary active metabolite.
good luck.