>>1familiarize yourself with comfy-ui:https://www.comfy.org/then use:https://civitai.com/ for extra tools/addons/models to suit your needs.
also keep in mind, you want to be running at least 12GB v-ram for videos.
theres plenty workflow templates available in comfy-ui itself to get you started. there are other softwares, but from my experience comfy-ui is easiest to get started