Yes, I took the computer-based test.
For writing, I used sample questions from the same that website I mentioned above.
https://www.english-exam.org/IELTS/general_writing_samples_task_1/
I solved some of these questions on my own and then compared them with the answers given there. It gives you a really good idea of what to expect and how much to write. Also, there are some very valuable tips given on top of each writing sample. They are quite handy, be sure to go through them.
For the speaking part, you just have to know the pattern of the exam. It is available on all the resources that I mentioned earlier. You can choose some sample questions from the websites above and practice answering them in front of a mirror or with a friend. Try to improve your vocabulary and speak English as much as you can in daily life. It will give you confidence to speak when you appear in the actual test.