Great question. You will know if you are a practicing Christian.
If you're Catholic you can do the following basic things:
- always pray everyday (not just one or two prayers but daily rosary, 3 o'clock prayer, Divine Mercy chaplet, Angelus/Regina Coeli, etc.)
- frequently go to confession (weekly, bi-monthly or monthly) after reading an Examination of Conscience (plenty of this online)
- go to daily mass
- read the Bible daily or at least 4x a week
- visit Jesus daily in the adoration chapel and spend at least 30 mins + listening to Him
- read the Spiritual Exercises of St. Ignatius of Loyola
As for other Christian denominations, the best example I can give is the Christian musician/singer Forrest Frank. Watch interviews of him and you'll know what's up!