If you can't walk up to a person and say "Hello, my name is _______, there's work to be done.
Yes, pick up lines work to a varying degree especially in a place where a person is looking to meet someone to have sex. There's also the school of thought that meeting in a natural, funny way like making a funny observation or joke and taking it from there or even being cocky at first is a stronger way.
But if you can't just say hi and introduce yourself confidently then that's a sign that your self esteem is weak.
If strangers can still get under your skin by passing a crudely formed judgement on you, there's work to be done.
Most people think the best of you. That's a great mindset to have and when you have it it often brings it to truth. However, there will always be those few who enjoy the freedom to pass judgements on others even though they don't know them at all. It's fun because it makes the other person feel certain and strong in their beliefs at the expense of the other person's feelings. The thing is if your self esteem is weak you will tend to care about the consensus that you are awesome. In other words, if you care about being looked down on your self esteem is weak.
If you care about the competition, there's work to be done
This is trickier because many believe competition is a key to success. I would not agree. Competition appeals strongly to the ego...it makes us think that if we do better than others we will feel better about ourselves and enjoy more happiness. This is the lowest form of self actualization. To believe you're in competition with anyone is to believe you are in competition with everyone to some extent. If you don't feel any need to work if you're not competing with anyone that's a sign of low self esteem and if you feel like others are threat to you because they'll take valuable resources from you that's proof that there's still work to be done because you feel you need these resources money, power, sex to be ok when you don't. everything outside of yourself is an enhancement not a need.