New to Sharepoint and Teams_best practice for creating client folders/site

Moving from a file server mindset to SharePoint is definitely a shift, but it's worth planning it properly from the start.

For a company with four office users, I would keep the structure as simple as possible rather than creating lots of SharePoint sites.

A good approach would be:

• Create one primary SharePoint Team Site for the business.
• Use document libraries (or a small number of top-level folders) for major business areas, such as:
  • Clients
  • Employees (with restricted permissions)
  • Equipment
  • Vendors
  • SOPs & Templates
  • Finance (if applicable)
• Within the Clients library, continue organizing by Client Name > Project, since this matches how your team already works and makes files easy to find.
• Only create additional SharePoint sites if a department truly needs separate permissions, ownership, or a different lifecycle. With four users, that's probably unnecessary.

For Teams:

• Think of Teams as the collaboration interface, not the storage location.
• Create a Team (for example, "Office") connected to your SharePoint site.
• Use channels only for ongoing collaboration where conversations and meetings are important—not as a replacement for your folder hierarchy.
• Avoid creating a channel for every client, as that quickly becomes difficult to manage unless each client has active discussions.

A few other best practices:

• Take advantage of SharePoint metadata (e.g., Project Status, Year, Designer) if you need better filtering later, but don't feel you need to implement it on day one.
• Keep permissions simple and assign them at the site or library level whenever possible instead of on individual folders.
• Use version history instead of creating files like Proposal_v2_Final_FINAL.pdf.
• Sync the main libraries with OneDrive if your team prefers working in File Explorer, while still keeping SharePoint as the source of truth.

Given your size and the type of files you're storing (CAD drawings, PDFs, photos, spreadsheets, proposals), a single SharePoint Team Site with a well-organized Clients library is likely the easiest to manage and will scale well as your business grows. You can always split content into additional sites later if your needs become more complex.