Need Advice: Free Trial or Freemium?

In the next few months, I'm going to start charging for my product. I am trying to decide between a feature-restricted freemium model or a free trail model for the initial approach. I would appreciate any thoughts, resources, or learnings from anyone who has had to make a similar decision with a B2C product.

My product is a mobile app for iOS and Android that helps Chinese learners grow their vocabulary through daily practice. I've seen steady user growth and strong retention with the initial MVP. My goal for the next phase is to determine if people will pay to use this product, get a general idea of what they would be willing to pay, and to start generating revenue to put back into the business.

I'm also going to be contracting a new dev team for the next phase of the project as my initial team has rolled off of the project after launching the MVP. Given the situation with this new team, I may not have resources to easily test different pricing models right off the bat.

Any thoughts or resources related to freemium models vs free trial models would be helpful. A free trial model seems to make sense since it would be easiest to implement, but I'm worried about losing word-of-mouth growth by eliminating long-time users of a free version. On the other hand, without the ability to test at the outset, I worry that a freemium model might be risky.

Most other apps in the space use a feature-limited, subscription freemium models that charge different price tiers depending on renewal cadence (1 month, yearly, lifetime, etc).

Thanks for your thoughts!

(Also, if anyone knows a react native developer that could be interested in this project, let me know. I'm going to be located in Singapore come January so someone in that region would be preferable, but not a requirement.)