Self-studying accountancy within Big4?

I'm currently working for one of the Big4 firms in a non-accounting role (Technology Consulting). For improved career stability, resilience, and the possibility of pursuing self-employment (e.g., starting a business as a private accountant), I am interested in pursuing a conventional accounting qualification.

Q: If I were to self-fund the costs of further study in ACA, ACCA or CIMA alongside my current role, what additional experiential requirements would I need to need to fulfil before I could call myself a 'qualified' accountant?

Q: In my current position within a Big4 firm, are there any other opportunities to consider which might help me achieve my objective? I imagine there will be some advantages, but I don't want to discuss this with my direct team for obvious reasons.

Any advice and insights would be very welcome - thank you.