What does be honorable to yourself if you wish to associate with honorable people mean?

To be honorable is to be worthy of honor.

Simply put, people look up to honorable people because of their status or what they have done in their past. A honorable person may be brave, honest, noble, successful, etc. And they tend to achieve these qualities in a honest fashion.

These type of people will most likely want to be with other people of this type. So if you want to be in their company you will need to be like them.