Making Mods

Hey guys Im GUSTAMINECRAFTER im new and i wanna know how to make mods... if
ANY of u guys know lemme know k? so lemme just tell a lil story
i am a pro minecrafter i have been playing 3 years now the new updates are great i know some of u are probably new just like me so hey why not get along? i usually make worlds HUGE worlds with world edit i use them to make costum maps but i always failed.... how am i gonna tell my worlds if i always fail? anyways thanks for listening
i hope u have a bright future BYE :)

MEEEEEEEEEEEEEEEEEEEEE GUSTA!!!!!!!!!!!!!!!!!