1, daily life
When two people are together, in fact, many times, they don't talk about some in-depth topics. Generally speaking, they are talking about their daily life. Especially for long-distance lovers, in fact, because they are not in one place, they often want to share what they did or ate with their other half today.
2. The other party's study/work
If you two are still students, you can talk to your girlfriend about your study and see if the other party has any learning difficulties or how the school teachers' teaching style is and how you get along with your classmates.
Step 3 plan for the future
If you two have been together for a long time, you can actually talk to each other about your plans for the future and see what they have planned for the future.