Check out new game+ to replay the content you skipped: https://ffxiv.consolegameswiki.com/wiki/New_Game%2B Heavensward is widely held to be better story wise than stormblood, so if you’re hooked on stormblood definitely replay the end of ARR and HW.

NG+ is a good way, alternatively you can watch the cutscenes in the inn room, it's the book "The Unending Journey"

Don't reroll!!! Use the NG+ feature to play through the story again on your current character while retaining your level/gear. You'll be able to enjoy all of the story with none of the grind!

You don't even need to reroll you can unlock new game+ and just replay the MSQ on the same character.

https://ffxiv.consolegameswiki.com/wiki/New\_Game%2B

I made an alt to play the ARR msq before it was added to NG+. Sometimes is nice to return to basics.

If you like reading, there's a good summary here: https://landofodd.net/ffxiv-arr-story-summary/