wrestling with unconditional love

The concept of unconditional love for everyone on the planet is mind blowing for me.

How do I change my thinking from ONLY loving and liking those who I am naturally drawn to, to seeing people for their humanity and goodness instead of being repelled or judgemental?

I understand how pets like dogs give the gift of unconditional love to their humans. What are they thinking?

I am not sure how to even start.

Circumstance: other people
Thoughts: some people are not lovable, repellent and I don’t want to have anything to do with
Feeling: not open, dislike
Action: Stay away from, don’t talk to,
Result: Limit my life to only people who are like me

Circumstance: other people
Thoughts: often I don’t like certain people at first and may slowly learn to love them, but it doesn’t happen automatically
Feeling: observant, open to possibility, reluctant
Action: get involved though still judgemental
Result: Not immediately loving, standoffish