And the things that thou hast heard of me among many witnesses, the same commit thou to faithful men, who shall be able to teach others also. - 2Timothy 2:2 After you have prayerfully read and examined scripture and applied what you have learned in your own life, you are ready to teach others. This is known as discipleship. You can teach others what you have learned in scripture and share with them how they may apply these scriptures in their own life.
That they may teach the young women to be sober, to love their husbands, to love their children, - Titus 2:4 You don't have to be a Sunday school teacher or hold some specific office in the church to teach. You can teach by simply sharing in a subtle way what you have learned. For instance, when you humbly forgive someone that has offended you, you show or demonstrate God's love and forgiveness. The knowledge of this love and forgiveness came from studying and applying scripture.
Let no man despise thy youth; but be thou an example of the believers, in word, in conversation, in charity, in spirit, in faith, in purity. - 1Timothy 4:12 Note, that you also teach others by the example, or by the lifestyle that you live.