OK it sounds to me that you want to get into lip sync as to ways and means to practice the craft and not get involved in constructing the necessary assets?
An option in this area could be Metahuman which you could import into UE5 or use the tool available through examples to examine how it’s all constructed.
Another option is Daz Studio along with the Genesis 9 framework where once again you can practice using the provided morph targets.
Both are free as far as the need to make a character talk with out having to start from scratch building stuff in Blender but once again there is the learning curve to tend with.
So no starting from scratch is not a requirement or necessary. For example
Could not find an example for G8 or G9
If you are interested in Metahuman you have options as well
Sorry for the hard love but a negative response is a good way to shut down a topic. A better approach is just to say you will look into it, or say you already have but does not fit your needs, and the refine your question as in the idea you want to practice as a means to learn and I’m sure you could motivate a conversation as there are no fixed pathways to this chaotic art form 