Rooms can fall into three primary levels of difficulty. You can distinguish them by the color of the bar on the right corner of each room at the following link: https://tryhackme.com/hacktivities. You can apply the difficulty level as a filter when searching for rooms:
Green: Complete beginner to easy rooms;
Yellow: Early intermediate to intermediate rooms;
Red: Advanced and insane rooms.
Moreover, it is essential to note that you will find two types of rooms: Walkthrough and CTF/challenge rooms. The first ones will guide you through an argument with explanations, examples, and clarifications. The second ones are meant for you to test yourself and are designed with a hands-on approach.