It is very important to generate a good attitude, a good heart, as much as possible. From this, happiness in both the short term and the long term for both yourself and others will come.
Our visit to this planet is short, so we should use our time meaningfully, which we can do by helping others wherever possible. And if we cannot help others, at least we should try not to create pain and suffering for them.
As social animals we need friends, but we make friends on the basis of trust, which comes about as a result of affection and concern for others. You can’t buy trust or acquire it by use of force. Its source is warm-heartedness.