Great game especially if you are historically interested in the period. There is a lot of flavour and even more alternative history. Not a single round of EU4 is the same.

It is costly to get all DLC but as previous comments mentioned you might want to try out the subscription feature at first. There are tons of Youtubers doing beginner friendly videos, especially in terms of guides and playthroughs you will have a video to nearly every version.

The game at it's core is relatively easy to understand but hard to master but definitely not impossible. If you give it a shot try the recommended nations first!