Put in simple terms, asexuality is a lack of sexual attraction towards other people. There are many different ways to experience being asexual and it is often referred to as a spectrum. There are subcategories under asexuality such as demi-sexual in which people may only experience sexual attraction towards someone once they form a connection and bond with them or grey-asexual, where people may still experience some sexual attraction and feel that they fit somewhere in between being asexual and non-asexual.
Some asexual people may also identify as aromantic—this refers to a lack of romantic attraction to others. You can still experience sexual attraction being aromantic, just like asexual people can still experience romantic attraction, but some people are both and only ever feel platonic appreciation for other people. Everyone's experience is different we all have different ways of feeling attraction or a lack of attraction. Similar to asexuality, aromantic identities have a spectrum that are used to describe the different ways they do or don't experience romantic attraction. Grey-romantic and demiromantic are used in the same way for the aromantic spectrum as the asexual spectrum just referring to romantic attraction rather than sexual. There is also lithromantic or akoiromantic which refers to someone who only experiences romantic attraction until it is reciprocated—then it fades or disappears. On the other hand some identify as recipromantic where they need romantic feelings to be reciprocated in order to feel them at all.
There's a lot of complexity in these identities but it's important to know that you don't need to have it all figured out. Labels can be beneficial in understanding how you feel and identify, but they aren't everything. If you don't experience romantic or sexual attraction it's completely fine and normal. There are other types of love that can be just as fulfilling, like platonic love.
More resources on asexuality and aromanticism: