How often do I need to practice Oud in order to show progress?

Consistency is key for progress.  You need to practice regularly and in a very disciplined manner.  Start with warm-up and technical exercises before jumping to the fun part of playing a piece or a song. Ideally, if time permits, practice a minimum of 1 to 2 hours per day.  A minimum practice of 15min every day is important if you don’t have time for longer practice sessions. Practice every day and don’t wait too long between practice days. Better practice 15min every day, then dedicate one or two days per week for longer practice sessions. Also, always use a metronome, especially if you’re a beginner. I cannot stress enough how important a metronome is. Just use it.