Simple platform like monday.com or similar manage client tasks

we are a very small digital marketing agency ( 3 people) with 20 clients we use MONDAY .COM but dont need all the features

we simply would like to following a very simple white label version of monday or similar

1. to add a client, with their details,
2. be able to upload documents,
3. option for them to be able to upload documents i.e like a google drive type thing
4. task list to assign an employee (there are 3 of us) and can mark it as pending , or completed, so we get notified by email or whatsapp.

please share a demo or example.