you can search online for classes.
A very good advice and by just google you will find many free online English tutors that has made the tutorials free online. I will also advice at op to download Grammarly application from Google play store from Apple store if he has Android or iPhone as this is one of the best application that shaped my writing English.
Whatever ways that OP can be find online would be a good way to enhance his skills, if he's really wanted to achieve such goals he'll then be able
to get something online tutorials or guides can help him to improved, just don't lose hope and keep trying your best.