It's OK if it works!
I'm assuming you're asking about a cloth diaper
? If so, fold the diaper so you place extra padding over the penis to catch the urine
Fasten it at the baby's hips with tape - or with diaper pins if you're brave. Disposables are probably easier to use, especially if you are new at this! remember, it only matters that it works - not how it looks! good luck.