Conlangs
Do you know what a conlang is? A conlang — or constructed language — is a language that, instead of forming from evolution, has been made by one person (sometimes a group of people). Some famous conlangs include Esperanto and Klingon. Many people make conlangs for different reasons. For example, Klingon is a language that was used for the film Star Trek. Sometimes, conlangs are made simply just because the creator feels like it, such as the conlang OJi, which is one that I made. Other reasons can be secret communications, micronations (unrecognized nations; a nation not in the UN), films/books/stories, or even just that the creator(s) feel like it.
How you can make your own conlang
If you want to make a conlang, the first thing you should do is to determine the writing system. You can use an alphabet (such as Cyrillic or Latin alphabets, or just make your own), or character system. Another thing you should do early on is to pick a name for the conlang, both in your conlang and in your native language. Then, choose a grammar style and rules for the conlang, for example, Verb + Noun + Subject + Time + Frequency + Place + Punctuation, etcetera, and rules like how to know when the word is feminine or masculine (or do gender-neutral words like English). Then, you should start making vocabulary. Good ways to write this down can be a doc or sheet.