Best way to integrate revenue data for active accounts?

Hi,

We just started using Salesforce as a customer (Accounts) database. But, we generate tons of data on each Account in both our data warehouse (via Google BigQuery), regular Google Sheets, and Shopify. For example: revenue per order or time-period, forecast (monthly and annual), average order value, order frequency, last order date, etc.

My question is: What's the best way to collect and track this data in Salesforce?

We're familiar with building reports and dashboards but we simply don't know the right place to put this data (we're new to Salesforce!). Should we somehow create an "Opportunities" or "Campaigns" structure? Or should we create some custom object(s)?

There must be companies like us out there who have existing accounts and want to track their performance over time! How do you do it? Examples and ideas welcome!