Don't aim for speed! Aim for typing without errors and - more importantly - a constant rhythm. Music helps. Start extremely slow and spell out each word letter by letter in your mind.
You should find many exercises out there for how to get started with all fingers. But the key is really to slow things down. It's very much like learning an instrument.
If you keep practicing this say 10-20 minutes per day you'll soon see progress. Speed then comes very naturally and without much effort.