Creatives & Social Media marketer for different social media platforms

We are looking for someone who can create creatives such as(posters, banners, posts, flyers, video, youtube thumbnail, etc.) for social media platforms, and who can write captions, with keyword for the posts on social media for our organization and for our inhouse organization / partner organizations. And creating different strategies, and campaigns for the social media platforms like(Youtube, Instagram, Facebook, LinkedIn).