Give it a try with minimal investment
If you are someone who is hesitant to start journaling because you have never been able to commit to it or are unsure if it is "your thing," start with a basic notebook. That's really the only essential element, plus a writing implement, that you need. A fancy journal is not a requirement. A spiral-bound notebook serves your purpose and it is inexpensive, so the investment is minimal.
Try to schedule a time to write regularly. It doesn't have to be every day, but in the beginning, set a schedule and see if you can stick to it. You may find that it becomes a habit or you miss it when you don't write. If that is the case, it may be time to upgrade to an actual journal.