Here are some websites that could be helpful to you.
On the Cambridge English website you can find information about the exam, there is also a section about preparation. Here they provide some free materials that can get you started. It is practice test materials from the teams that make the test, so they are a great places to start. They have sample papers for different skills areas e.g. writing, listening etc There are samples for both paper-based and computer-based tests to get you used to how the exam works and its layout.
Another site that looks really helpful to B2 First learners is Flo-Joe:The place on the web for Cambridge exam preparation. This seems to be a really popular site. This website can help and offer guidance for all Cambridge suite exams, not just FCE. You can sign up for a weekly email containing tips and advice on how to take the exam, they recommend study materials, have some free exercises for you to practice, access to a word bank they have created, and you can join their FCE community page . Take a look!
A website call FCE Exam Tips also looks quite good. This site contains videos about (FCE) B2 First and exam skills etc (linked to Youtube). They split the materials by skill area – reading, writing, listening, and speaking. Each skill section contains a breakdown of the test, suggested topics, and strategies for answering the questions. This is helpful if you are struggling with specific questions types, skills, or areas of the test. The site also has articles relating to exam for you to read. There might be something in these that really help you. The website is https://www.fceexamtips.com/
One final website is actually a company that provides a platform for you to really train and focus on the exam. They have sections for study plans, grammar and vocabulary practice, full exam practice, and the ability to track your own skill development. GlobalExam has a proven success rate with supporting test candidates to achieve the grade they want in B2 First (FCE). Take a look at their website, try the free area, and see if they can help you.
Good luck in your B2 First exam!
Good to know: practice is essential, and you have many ways to study for the test. You can find information here about all the study materials for FCE: books to study FCE, free sample test to study FCE.