Half-way to alpha / need some advice

Looking for guidance and book recommendations. I saw the list of books in the recommended reading, but there's quite a few and I'm not sure which will give me the most immediately applicable advice.

I've written a strategy in pinescript using the opening range breakout strategy, and the performance overview looks good. For some stocks the performance is losing money, but I've identified 2 inputs I can tweak to turn most stocks profitable. Those inputs are:

1. enable/disable shorting and enable/disable longing
2. disable trading if the opening range exceeds an arbitrary multiple of the opening range ATR

So, I think what I need to do is create/discover some factors that I can use to determine — on a per stock basis — when the strategy should use long-only, short-only, or long+short, and what multiple of ATR to use. I've been watching the Quantopian "Learn From The Experts" videos, which are great, but I was hoping someone would be kind enough to tell me what I need to do next.

I don't have a background in data science, but I am a developer and I've gotten comfortable with jupyter notebook.