There are paid and free tiers of Notion. You can use a free one, but this is more of a trial than anything else. This is because Notion employs "blocks" to limit the amount of time that freemium consumers may use the product before being compelled to upgrade. Elements such as pictures and chunks of text are all examples of blocks. The number that you use will add up quickly, which is why it’s worth upgrading to a paid tier if you’re doing to use it a lot.