It’s really about The Pitch, not about The Deck. It’s about your traction, and an investable story. Not about a choice between Powerpoint or Google Presentations.

There are places where you can start, such as YCombinator. Or you can turn to paid options such as paid startup dev studios. Self-plug alert: I run one and we’re called Asper Brothers. You can also learn all the ropes the hard way just for fun. That’s also great. Just ensure you’re solving someone’s problem actually and that there’s enough people willing to pay you for solving this problem. Coming up with ideas just to build something is a very risky path.

Avoid seeking VC if you’re pre-revenue/pre-product. Money isn’t your immediate need.
Gather potential users for customer interviews (search “in-depth interviews”). Conduct 6-8 to identify patterns and focus on pain points.
Next, build an interactive prototype for user testing.
Set aside $1000 for ads, build a landing page, and create a waitlist.
Then, consider approaching angel investors.