Why do my parents treat me differently than my sister?

so we are about 1 1/2 years apart! we are kinda close but my parents treat her better... like for example she is in public school and i'm homeschooled, well after school they just HAVE to know EVERYTHING about her day, then they will start laughing and i will be like 'what's so funny?' and then they stop laughing and are like 'nothing just forget it' i feel soooo left out! my parents love me but they don't realize they treat my sister better than me! they just LOVE her and not me (not as MUCH they love me but just not as much) like my sister is SUPER artsy and i like art but not that much i'm just not good at it! well my sister has had her art in this 'museum' and art shows and she did a backdrop for a play and she's just got the spotlight where when i do art for my mom and give it to her she's just like 'oh thats..... nice....' and then the next day it's in the garbage. well lately i've been hanging downstairs in our room (my sis and i share a room) and then i hear them talking upstairs and my mom will ask my sister what something is and my sis doesn't know so i will run out of my room and be like 'what is what?' and then my mom is like 'oh nothing never mind' and i'm like ' i really want to know' 'just forget it!!!!!' and she yells at me for not doing something she 'told' me to do (she says she told me but i would've remembered) and i tell her she never told me anything and then she yells at me and asks my sister who then takes her side!!!! i just feel they don't care about my school or my life! oh and the one i HATE my sister is in karate, well i want to do gymnastics, and i asked my mom and dad about it (my dad is in karate with my sister) and gymnastics is on thursday nights (7:45-9:00) well we have a little sister who goes to bed at like 7:30-8:00 so i can't be in gymnastics because my little sister (gymnastics is on the same night as karate) has to sleep, well that's the only teen one otherwise i have to go to another gym and be with the 5 year olds! but anyways! what should i do? i want to be in activites but i can't because my sister has stuff like ffa, karate, an art thing, stuff like that! we live an hour away from anything big like tennis, swimming, gymnastics, yea! so what should i do? thanks! and sorry it's long!