For Your Marriage - https://www.foryourmarriage.org/dating-engaged/ - awesome resources, articles on engagement, especially on planning a Catholic wedding, from the basics to budgeting to planning the wedding.
Formed.org - https://formed.org/– It’s like Netflix, but full of award-winning Catholic videos, movies, podcasts, and more. Our parish pays the annual subscription fee, so it is free for you to use! You can find series on each of the sacraments, and really on any topic of the Catholic faith.
The Five Love Languages - https://5lovelanguages.com/ - Take the free online assessment to learn your love language and start communicating better with your future spouse.
Foundations Newsletter by Steve & Kathy Bierne- https://snkpublishers.us/foundations/ - Fantastic couple who has a ministry dedicated to supporting Catholic marriage. They have a free online newsletter, which I have attached the latest edition.