First META Ads Campaign Setup

I need help setting up initial paid META ads for my Shopify store (and possibly help on-going with future ads / campaigns). I’m running into some issues that I believe are simple to clarify and fix, but since this is new and somewhat foreign to me, I need some help. I will only do this using a screen-share session (zoom?), with me doing the work (so I learn how) and being guided thru the issues. For this first ad, I simply want to do a campaign for 4 separate/ unique products from my Shopify store. I have already integrated my META Business Manager account with my Shopify Store and can see my Shopify products from META. Pixel is installed. I’m getting stuck trying to get all 4 products in unique ads – or a carousel. Not sure where I’m lost and stuck. Also, when attempting to set up a campaign, I am being asked to paste Pixel “purchase event code” – on my “order confirmation or purchase completion page” – and that is out of my comfort zone. (Do I really need to make code changes?) For this first test campaign, I want to spend $40 per day, 3 days total, $120 total spend max. TBD - Carousel or 4 unique campaigns for each of the 4 products. I want to do this ASAP today, tomorrow, ASAP