Modern Educational PowerPoint Redesign (Sales)

I have the slide content drafted and roughly laid out; what I’m missing is the visual polish. The deck is meant for an educational session, so clarity and flow are critical, but I want it to look modern and sleek rather than corporate-stiff... (Budget: $30 - $250 USD, Jobs: Adobe Creative Cloud, Adobe Illustrator, Adobe InDesign, Adobe Photoshop, Graphic Design, Logo Design, Powerpoint, Visual Design)