Facebook & Google conversions API + general tracking & catalogue setup

I have a new facebook page for my business and would like the most reliable way to track conversions etc and for somebody to setup my catalogue correctly. I have read that API is preferable to pixel as results are more accurate.

I would also like to know if my current google ads tracking setting is the most reliable and if not, change it to the most reliable option. I have a lot of conversions that aren't tracking due to adblockers etc.

I would like to avoid adding more plugins to my site.

Please provide quote and timescale. Thanks