First of all, the exam is $70 and change. This means there is no need to spend much (or any) money studying or to overstudy. You can always take it again without laying out a lot of money if needed.
There are a number of ways to study depending on your preferences and what you have access to. Regardless of what you choose, read the official exam page so you know what to expect.
Option 1: Resources from HashiCorp
HashiCorp has web pages references that they say are useful for the exam.
All three are fine for learning. Just be aware they have a lot of info you don’t need to know. I recommend using another resource for review the day before even if you use this initial.
Option 2: If you have access to ACloudGuru
There is an ACloudGuru course online. It is about 8 hours of content including labs/quizzes. I didn’t try it because i was studying mainly offline. However, I did use them for the AWS cert. The material was good/consistent enough that I feel comfortable recommending site unseen. There’s a free one month trial if you aren’t a customer.
Option 3: Whizlabs/IPSpecialists
There are 25 questions online for free. This is a subset of what is in the book. The quality/lack of consistency is representative of the book. You can see if that bothers you before spending any money.
Option 4: Medium blog post
The title of this medium post says this is 250 practice questions. It is in the sense that there are question marks. Not in the sense of practice questions. What it does do well is serve as an awesome review of what you need to know for the exam.
Option 5: My study notes
Like option 4, this is a good way to review.