im not big on programing and will probably post animations only, which are mp4 but idk how to add them is there a way ive seen a few do it

You cannot import video format files into a Scratch project; but you migth convert a video as a GIF image and add the sound as a separate stuff.
Both, video and sound, must be quite small in bytes…

if its long, chop it to small gifs, and chop the audio into small mp3s, if its short, chop it into a gif & mp3