We have some new Muslims who have complained that they enter Islam and are not taught the basics. What is the best thing to teach them first. ( some don’t even know how to pray).

Start with the meaning of the two testimonies of faith and tawhid, then the prayer and the purification for it, taught in practice, with al-Fatihah, and what t o say in the salah, but very slowly and whatever they are capable of, so do not burden them. Then the rest of the religion in order of importance, gently and gradually. This is the order in the hadith of Mu’adh raḍiyallāhu ʿanhu (agreed upon).