Start with Metta sutta: memorise the thought section and recite it mentally and recite it as much as you like. Then based on 5 precepts which bring freedom from fear and suffering to yourself and others you can’t go wrong.
Lovingkindness
(Metta Sutta)
This is what should be done by one who wishes to realize and live in peace: He should be capable, upright and perfectly honest, easy to admonish, gentle and not conceited, content with whatever he has and easy to support, not busy and have few possessions, calm, wise, well-mannered and not attached to lay supporters, and he should not perform even the smallest act of misconduct for which he would be blamed by the wise.
His thoughts should be:
“May all beings live in happiness and peace, may all beings experience happiness”.
“Whatever beings there may be without exception, the feeble, or the strong, the long, large, medium, short, small and minute, those I have seen and those I have never seen, those living far away and those living nearby, those who are born and those who are yet to be born; may all beings experience happiness”.
Let him not deceive another or despise anyone whatsoever in any place. Let him not wish harm to another because of ill-will or dislike.
Just as a mother would give her life to protect her only child, in the same way let him develop an unlimited mind of loving-kindness towards all beings.
And let him develop an unlimited mind of loving-kindness radiating to the whole universe, above, below, and across, without limit, without enmity, without ill-will.
Whether standing, walking, sitting or lying down; for as long as he is free from sloth, being established in constant mindfulness of loving-kindness, this is said to be the best way to live.
Without taking up wrong views, being virtuous and possessed of insight, he whose attachment to sense pleasures has been removed, he will never be reborn again.