On doing, rather than thinking and talking about doing

'You could read every book in the world on swimming and still not know how to swim.  To learn to swim you have to get in the water' 

Kelly Wilson

What else is this true of......?  Creating, loving, arguing, being a good friend....

By all means read the instruction book and ask for advice and encouragement.  Absolutely, only risk yourself on endeavours that have meaning for you.
Definitely, start in the shallow end, with armbands (floaties/waterwings).
But know that, however scared you are, at some point, you have to get in the water.
Don't leave it too long - life is short.