What do I need before hiring a web designer?
You need three things: a clear goal for the site, basic brand assets (logo, colors, fonts), and an outline of your content. Everything else can be built collaboratively with your designer.
The minimum viable brief
1) The single most important goal of the site (book consultations, sell products, generate leads, build authority). 2) Logo and brand colors, even if rough. 3) An outline of pages and what goes on each, even in bullet form. 4) Examples of 3-5 sites you like and 2-3 you do not, with notes on why.
If you have these four things, any competent designer can quote and start your project.
Things you do NOT need before starting
Final copy, professional photography, brand guidelines, or a perfectly defined site map. A good designer can guide you through these as part of the project.
You also do not need to know your CMS, hosting, or stack. The designer should recommend what fits your needs.
Red flags from designers
If a designer cannot quote without a 50-question intake form, they probably have a slow process. If they refuse to share a fixed price and insist on hourly, expect scope creep. If they cannot show recent work in your industry, ask why.