Client portal software for small business

Build a client portal for my small business. We are a small team, we have no IT person, and I want it simple.

Create a shared database with four tables: clients (business name, contact name, email, phone, address, active or inactive), jobs (linked to a client, job name, short description, appointment date, who on my team is assigned, stage of Quoted / Scheduled / In progress / Done, quoted price), invoices (linked to a client and a job, invoice number, amount, date sent, due date, paid or unpaid, balance due) and files (linked to a client, file name, the file itself, uploaded by, date added — quotes, photos, permits and signed paperwork).

Give every client their own login. A signed-in client must only ever see their own jobs, invoices, balance and files — never another client's, and never my internal notes, my crew's names or what a job costs me. On my side, staff can view and edit everything, and the owner can also add clients and hand out logins.

Build a client page showing their next appointment, open jobs, balance due and the files I shared, with a spot for them to upload a photo or a document I asked for. Build an internal list of every client with open jobs and unpaid invoices, oldest first. Keep an audit log of who changed what and when.