This YouTube channel offers some 70+ videos (March, 2022) with slowly and clearly spoken Mandarin with a standard accent. Each video is a story told entirely in Chinese, but with plenty of scaffolding to help you out, such as literal translations, images and gestures. The level is suitable for beginners, which makes this one of the few resources that use mostly Chinese to teach the basics of the language. They also sell products, but the videos on YouTube are free. Warmly recommended!
Their own introduction reads:
In our channel you will find content to study Chinese in the format of stories. At the moment most of our videos are part of the Slow Chinese series (videos including pinyin, hanzi, pictures and optional translation in English and Spanish) but we also have some videos with on-screen translations (literal meanings) and others with Chinese spoken at different speeds. We will keep exploring new ways of creating engaging stories for more student levels, and we wish you great success in your language learning journey! 加油