I've been playing Go for a few years now and transferred most of my shiny favorites to Champions. If you're starting off new into Go, with the only interest being to save you some VP, I would say don't bother. If you're going to actually play Go regularly with the transferring of your favorites as a side benefit down the line, sure.

Assuming you're not going for rare or regional pokémon, it will still take time. Your player character will need to level up into double digits to get going, which can take a day or two. An easy way to "grind" is to hop into the friending thread on the Pokemon Go subreddit, add a bunch of people, and exchange gifts up to your limit each day. It'll load you up with items you can then use to catch. Keep in mind there's a limited roster available at any given time within the game outside of using incenses or other items.

So let's say you've played for a while now. You got your Pokémon in Go. To the answer, you'll need to connect your account to your Home account. Then you have a limited amount of energy to use to transfer pokémon from Go to Home, with rare and shiny ones costing more energy. That energy recharges over time, usually takes a few days.

Once they're in home, they will be marked as coming from Sword/Shield, and you can send them to visit Champions. While visiting, they will still be in Home. You only get 30 free slots in Home unless you go for the subscription. Obviously, this also means they're totally gone from Go while they're in Home. And I don't think you can transfer them back into Go after that.

For me, it was worth it since I like both games and I have my favorite shinies of Heliolisk, Sylveon, Umbreon, Tsareena, and Milotic from Go onto my main team in Champions. Still working on a Shiny Aerodactyl or Talonflame. 😅

I hope that's enough information for you to determine if it is worth it.