Gw2 Core is free so you can get an account started that way.
Take a read through this
https://help.guildwars2.com/hc/en-us/articles/115010688287-Guild-Wars-2-Path-of-Fire-FAQQ: Is Heart of Thorns included when I buy Path of Fire?
A: No. We've provided the option to purchase each expansion individually or together as a bundle. This means that if you already own Heart of Thorns or only want to play Path of Fire, the option is available to purchase each expansion on their own.
If you want both expansions, we recommend adding Heart of Thorns during checkout, as this will allow you to purchase both expansions at a discount than if buying them individually.
•To purchase Path of Fire, visit our official store.
•For more information about Path of Fire, visit the official site.Sadly there's no good tutorial for their account interface that I have seen, it's intuitive though just something infrequently used.
https://www.reddit.com/r/Guildwars2/comments/9rc9wg/psa_path_of_fire_50_off_sale/A few people are probably in the same boat.
This post was edited by MrSkales on Oct 26 2018 06:21pm