What should i do about my little brother?

ok well i feel super sorry for my little brother, he is 5 and he is super weak, he is shy around others, he doesn't no his alphabet and ever time we try to teach him its like he has no long term memory, he also gets really mad at the littlest thing, he turns bright red and has a fit it bugs me. he also walks really odd, his feet aren't straight, he walks awkwardly, with his feet coming in please give me some advice on what i should try! i don't want him to grow up with a hard life