What’s the best way to go through all the training over time if I don’t know which specific roadmap to choose?

It all depends ...

Do you have a project you are - or will be - working on?

What do you want to learn?

What do you need to learn?

Is there any marketing asset that you avoid because you don't know where to begin? 

If you have an answer to any of those questions, you have an answer to the question of which roadmap to choose. 

If you're still at a loss for which roadmap to choose, Joanna Wiebe (the founder of Copyhackers) suggests starting with either a landing pages or sales pages roadmap ... and always start with Researching. 

Either of which would look like this in the filters: 

Researching >> Landing Pages >> [choose the business type you're writing for] >> Acquisition: Leads

or

Researching >> Sales Pages >> [choose the business type you're writing for] >> Sales: 1-to-many sales