You have major homework to do and this is a google question. There are a lot of metrics and KPIs. Then you have those that support the KPI. Sales is a big one. Profit is another but WHY those numbers are what they are is very important because it gives you the info to market better. Two new store owners don’t understand but are also key are LTV and AOV. (not giving you the breakdown, google it). Inventory velocity, gross margin, net margin, are also part of it that may not be obvious.