how can I improve my singing voice?

i absolutely love to sing and id like to do more with it, like sing
for people. but i dont think my voice is really good. i think i can
sing ok, and when i was younger i used to sing in talent shows and i
came 2nd place in one and used to be really confident about it
sounding ok and singing for people (: but now i have this problem i
dont think i used to get where i get very restrained like i feel held
back when i try to sing sometimes? its like a barrier, to explain it a
bit better, and i really want to break through it. also my voice can
be fine and everything but then at random times it feels croaky in my
throat and i think thats sort of to do with the restraint.. could a
singing teacher help me break past this? i really hope so, because i
love to sing and id love to sing to people so it kinda sucks that i
have this thing happening thats made me stop.. :