This topic is rather interesting for me to write about.
When I was younger, I would find a way to try things that interested me.
Because of this, I've seen work as a fencing instructor, jazz musician, programmer/analyst and a brewer in a microbrewery.
I've had a real "Why not ?!?" attitude. But, age and a few truely massive failures have tempered my attitude. So, when you ask what advice I'd give to someone afraid of failure I'll be giving the advice to myself, too.
Look at what you've done in the past.
What has been a memorable success? How did it feel? How did you get there? What was the process/path you took to engineer that success?
Now do the same for a memorable failure.
What was the difference between the success and failure?
I'll go out on a limb and say it was probably preparation and commitment. If you have prepared to the best of your ability and will put in some work, chances of failure become less and less.
Decide what you want. Where do you want to go? If you don't know, you'll probably end up somewhere else.
Commit and prepare for that decision. Commitment doesn't mean quitting your job and selling your house. It means looking at your goal and holding it in your heart as something you really want. Preparation means putting in some work or study so you will know what to expect when you experience some of the bumps in the road. There'll still be surprises, but you'll be better able to handle them. You won't be perfect or an expert (yet), but trust your heart and enjoy the work.
Take action.Do something, even a small something, to move forward. If it feels good, do more.
If not, go back to preparation.
Hopefully I can take my own advice.