Before installing anything, understand the pieces involved.
THE ESSENTIALS
A domain, which customers type to reach you Hosting with enough resources for a shop, which is more demanding than a brochure site WordPress and WooCommerce, or another store platform An SSL certificate, which is not optional for a shop A payment gateway to take money
A way to deliver: shipping, collection or digital download
WHAT A SHOP DEMANDS THAT A BROCHURE SITE DOES NOT
More memory, because WooCommerce loads considerably more on every request A working cron job, since orders, emails and stock rely on scheduled tasks Careful caching, because cart and checkout pages must never be cached Reliable email, because order confirmations that never arrive cost you customers More disk space, since product images accumulate quickly
WHAT TO SORT OUT BEFORE LAUNCH
Your prices and whether they include tax Delivery options and charges A returns policy Who packs and dispatches orders
The software is the easy part. Deciding these is what takes time.