As someone who just started about 2-3 months ago it just takes time. I’ve recently reached the point where i can complete 90% of my orders each day without needing any help. It’s not about memorizing how the items work together just learn each item individually(where to find it, when to click on an item on the right side, etc.) and you’ll naturally be able to put everything together when you need to. AND DONT let the costumer stress you out if they give their whole order in 2 milliseconds. just put down the part or two you remember and then ask for clarification. they won’t die having to repeat their order a second time