It could be five static pages or a booking system with payments. Quoting before you know which is how a two-week job becomes three months, unpaid.
The build finishes and then everyone waits six weeks for photographs and text. Say it in writing early: the timeline starts when content arrives.
A one-page summary: what is included, what is not, what you need from them, the timeline and the price. Email it and ask them to confirm.
NOT included: logo design, copywriting, product photography, ongoing SEO, hosting fees, an admin panel, monthly maintenance.
Nearly every difficult conversation later is about something one side assumed was included. Naming the exclusions prevents almost all of them.