Want to create a language? It can take a lot of work to make it presentable, but the results can be amazing. To make your own, decide what sounds you want, create words, and hold it all together with a grammar. (Not necessarily in that order.)
Decide the phonology (sounds in the language)
What sounds distinguish words, and which don't? In English B/P do (bat and pat) In Korean p and ph do (put/phut) while b and p don't. Many English speakers see the and de as the same and free and three when it comes to pronounciation
Decide on phonotactics; which consonants go together and which don't? In English you can say "Spanish," but in Spanish the letter S cannot begin a word when followed by a consonant so it becomes "Espanish." Can you have consonants at the end of syllables? Not in Hawai'ian.
Construct a grammar. (May be done at the end)
Is it agglutinating, isolating, fusional or polysynthetic?