Normally for the first start
the most important thing is still get your website up asap
after your website is up only you can start to measure behavior of your website visitors
with more data that you have after few months or a year, you can plan for your next website to tackle all the behavior to increase conversion from website
There is no website that is launched at perfect condition
Even the biggest brand that you manage to name any of them also they keep updating and changing their website layout and ordering system to improve UI / UX.
Ecommerce website builders locals vs shopify