How do you use third party tools to optimize your campaigns?

Just signed up for a popular third party tool to help manage my campaigns / make my ad spend more efficient.

My dashboard is still syncing, but what would you say is the most helpful thing these 3rd party tools do?

I only sell 1 product in a fairly competitive space (home and garden, fertilizer-like products).

Can I use these tools to help me optimize my bids? What is the best way to find keywords to bid on?

I am a new seller (still in first month) if that matters. Spending about $100 / day and not profitable.