I think it depends on your experience and how much time you have.
For a big project - if your looking to convert from framework x to framework y - I think it's important to "vet" the framework and make sure it can do what you need to do. Most people can't see the future, so it's more important to get a grasp of the framework and if some point down the line, it can't do what you need it to do, that you can figure out another way or make it do what you need it to do.
If your just starting out in programming (this might be your first project), it might also be a good idea to read as much as you can about it. Most new programmers can't just jump into a complex project.
But for a seasoned programmer; someone with years of experience; after a while, they all start looking the same. Every language / framework - they're all based on the same basic ideas. There's only so many ways to write an array, or object, or class, or function - even most of the routing features I've seen across AJS, React, Vue look "similar".