The five-tool rule
For a first online business, use no more than five core tools: a website, checkout, email capture, planning workspace, and analytics.
This prevents tool research from becoming a substitute for publishing, selling, and talking to customers.
What each tool must do
Your website should explain the offer. Checkout should accept payment and deliver the product. Email should capture people who are not ready to buy. Analytics should show which pages produce action.
If a tool does not help one of those jobs, postpone it.
Upgrade only after usage proves the need
Do not buy advanced automation until you know what needs to be automated. Start with free tiers or low-cost tools, then upgrade when the bottleneck is visible.
A profitable tiny product with a simple workflow beats an expensive stack with no customers.