Start by assessing your own skill level. Can you hols a line? How closely? Can you maintain control in an emergency stop or when steering around obstacles? Those are for starters, and you can use other concepts to rate your own biking skills.
Then start by picking quieter and/or wider roads to start with, and get used to riding in traffic. As you adapt and gain confidence, you'll become more comfortable with ever increasing traffic density.
That's half of it, learning about specific traffic hazards such as cars turning right across your path at intersections will help you spot potential hazards before they actually do.
Lastly, consider that accident reports and data are highly skewed. You hear about all the people killed or injured, but not about the vastly greater numbers of people who aren't. With a bit of basic skill, and reasonable care, you can ride very safely in traffic, the same way tens of millions of others do. The reality is that bicycling is a reasonably safe activity and you shouldn't let imagined fears scare you away from it.
__________________
FB
Chain-L site
An ounce of diagnosis is worth a pound of cure.
Just because I'm tired of arguing, doesn't mean you're right.
“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN
WARNING, I'm from New York. Thin skinned people should maintain safe distance.