If you want to learn 3rd person - start with something short, and do it because you want to gain the skill, not because you think you need to. There are a lot of writers who do first person, and a lot of projects that need to be first person.

There's no way to get everyone to love your work, but I read both 3rd and 1st person works of many lengths and I enjoy them. (And I've read 2nd person, too, from old CYOA.)

Also, if you're willing, take a piece of your book you're writing, and write the scene again in 3rd person after you've done it in 1st. I find this can be a valuable way of testing the water to see what works better.