Executive Virtual Assistant for Startup

I'm looking to hire an executive virtual assistant to support myself and occasionally other administration. This is a long-term position that currently requires 20 hours per week commitment on average, and is likely to increase to full-time in the future. I haven't worked with an executive assistant before, so I'm trusting you to implement or suggest processes that you've seen as beneficial in the past.

Key/Important Requirements:
-Comfort working in a fast-paced startup environment
-Great English Skills
-Ability to be available during business hours most of the time (8am-4pm EST)
-Experience working as an executive assistant for a CEO/Founder

Additional requirements (nice to have, not necessary)
-Bookkeeping experience with Quickbooks, Brex
-Startup/Product-focused Project Management experience
- Social Media Experience

Possible Tasks:

Planning and scheduling meetings.
Setting reminders, and organizing prioritization
Recording the meeting (if required).
Researching and organizing data
Compiling expense reports.
Performing bookkeeping tasks.
Handling memos, reports, invoices, and related documents, including sensitive information.
Keeping confidential information
Manage information flow in a timely and accurate manner
Providing administrative support and assistance in additional related tasks