The label of 'friend' encompasses everything from immensely intimate platonic connection to people you just hang out with and everything in between. As a result of the complexity of the human condition, there is no clear cut guide to making friends, since a friendship can mean just about everything and every relationship will have its unique complexities that you'll need to navigate by yourself.
Broadly speaking, what you'll want to do (and what all 'how to make friends' advice generally boils down to) is expose yourself to social spaces. These will be places and groups where you'll be exposed repeatedly to other people that frequent the space and that you can become familiar to. SaSu is an example of a social space, although online spaces are more fickle and anonymous. From there, you can evaluate the regulars and interact with them.
Mostly all people are unique in their presentation, behaviors, and modus vivendi. People will also evaluate and observe you, just as you observe them. They may approach you, and if you so choose, you can also approach them, and interact with them. Eventually, from this, you can establish a more 1-on-1 relationship if the both of you choose. Anything from there will generally depend on you and them.
Interacting frequently with others socially, even if you're not making friends, will develop your social skills. This is generally your ability to act appropriately, avoid faux pas, and communicate effectively. A big part of this depends on your cognitive empathy, that is, being able to broadly predict how certain things will affect others under what context. The more developed your social sense is, the more effective you'll be at projecting yourself favorably, and you'll become more approachable. If you have certain neurodevelopmental conditions, such as Autism, it'll take more effort to develop. Preferably, you'll want to develop your social skills to attract the kind of people you want to have as your social circle, rather than being 'likeable' in a general sense.