I definitely recommend Figma for sketching web-designs. That's what I did for my software company and it was a lot easier implementing designs. If it's for just graphic designs I would recommend Photoshop and as a free alternative I heard that Canva should be great.
Hope it helps 😁
Figma for more intricate designs. Canva for simpler social media templates and ads. Jitter for cool animations (you can import your Figma designs into it).