My most important piece of advice is: "Do something (anything). If you don't do anything, you won't get anywhere. Make it your hobby, not a chore, but above all have fun!"
Don't be in too much of a hurry. You're setting off on a long journey and there'll be delays and frustrations along the way. Sometimes you'll be in the fast lane and other times you'll be stuck in traffic, but there will also be lots of interesting things and interesting people along the way. Take your time to really enjoy the experience.
There are many ways to improve your level of English, but only you can find the right way for you. Here are a few tips that might help:-
Improve your Learning Skills
Learning is a skill and it can be improved.
Your path to learning effectively is through knowing
Subjunctive (I suggest you do)