“I can help with anything” sounds flexible, but it leaves a potential client guessing what they are buying. A useful first offer explains one specific result you can deliver reliably.
Name the finished item
Replace a broad service such as administrative help with a concrete deliverable: organizing one supplied spreadsheet, formatting a short document or scheduling an agreed batch of approved posts. Choose work you already know how to complete accurately.
Describe what the client receives, the format and what information you need before starting. If the work depends on access to an account, agree on an appropriate access method rather than asking someone to send a password in a message.
Put boundaries around the task
State what is included, what is excluded, how many revisions are included and when the deadline starts. A delivery date should account for when the client supplies the required materials.
For example, formatting a five-page document does not automatically include rewriting it, researching claims or designing a new brand. Explain those distinctions before accepting the assignment.
Run a small practice project
Use your own sample materials to estimate the time required for intake, production, checking and delivery. Do not present practice work as paid client experience. Label it as a sample and explain what it demonstrates.
Then write a short offer that a stranger can understand without a call. If the client can repeat back what they will receive and when, your offer is becoming clearer. Expand the service only after you understand the work and have room to deliver it well.