One of the biggest hurdles to transition from a state of low self-esteem to a state of confidence is the ability to set clear goals for ourselves when interacting with people of interest and detect the lies we tell ourselves to spare ourselves from the hurts of rejection.

Let me explain: let's say you go to a party and manage to bond with someone you met. You exchange numbers then they suggest going out somewhere.

You can interpret this in two ways: either they want to further befriend you or they want the relationship to go further by giving you a hint of their level of interest (them asking you out). You are free to ponder which interpretation is right for however long you want to but this will ultimately lead you nowhere.

You need to choose for yourself what you want the relationship to become. And most importantly you need to stick with your choice until it becomes clear what the intentions of the other person are.

When two persons interact with each other with a potential for things to go futher there will usually never be someone who will directly state their intention. Most of the time one person hinting and the other person answering to the hints accordingly. It's mostly a game of indirect hints and undertones that can stop pretty quickly if the two persons are not on the same wavelength

Let's say you go to a date with the person you bonded with during the party. You want things to go further but to protect yourself from being rejected you tell yourself that you wouldn't mind becoming friends with the person if things don't pan out. Maybe you really don't mind. But by keeping in your mind the two possibilities you are much more likely to go the friendzone route because of how answering to hints works.

As soon as they give you a hint of their interest (e.g., "I would love to go to the museum event you just mentionned!"), if you are not clear on what your goal for the interaction is you may answer the hint with a "friend" answer instead of a "date" answer ("Sure, we can go with my friends!"). Even if you managed to keep a "date" frame beforehand, one wrong answer can confuse the other person and push them to stop giving out hints despite their interest in you too (Either because of insecurity or because they interpreted your answer as a "let's be friends"). And in turn seeing how they stopped giving you hints you might understand that they never wanted anything more than being friends from the start and that you were imagining things all along. And that's how two persons can stay in purely platonic relationships despite their interest in each other.

TL;DR: If you text or go out with someone and you want things to go further, clearly state your goal to yourself and work towards the goal by answer to hints given to you accordingly