If i have one tooth that pushed out in front of my other teeth by just a little (only i can really notice it) if i wear my retainer will 1 day fix it?

Probably not: A retainer probably will not fix the pushed out tooth. It will prevent it from shifting further however. To shift the tooth back into the proper position, you may consider invisalign.

It may help: Very minor tooth movement can occur quickly. If your retainer still fits and if you notice some pressure on the errant tooth, it may help in as little as a day. It will likely relapse back to where you don't want it just as quickly. If the retainer works, explore a more permanent type of retention with your treating dentist once it's properly in place.

Certainly possible: Wearing your retainers regularly should keep and provide very minor re-alignment of your teeth for years to come. Try your retainers in once or twice a week indefinitely and wear them more if you notice small changes as you've described. If there is a larger change or retainers are not fitting correctly, make an appointment with your orthodontist.