If you want to improve your finger-brain connection as fast as possible, I'd recommend taking 10 to 15 minutes each day (or more) doing finger independence exercises. The best one to me seems to be like this:

put all four fingers down on one string, one finger per fret. Keep all your fingers pressing down on the frets at all times, while you choose one finger to lift up. You might notice the first few times that when you try to lift up your ring finger, your middle finger might come up instead (or vice versa). This really shows you if you have a weak connection or finger Independence.

Then do the same thing but lift up two fingers while the other two remain pressing on the frets. Do every combination you can think of, then start to move certain fingers to the next string. Another thing that helps is permutations (remember back in math class?): https://www.youtube.com/watch?v=MVeyo352gpU

Good luck!