How do I buy hold and sell crypto?

Excuse me, could you please explain the process of buying, holding, and selling cryptocurrency in simple terms? I'm new to this and I'm a bit confused about the steps involved. Also, are there any specific platforms or exchanges that you recommend for beginners like me? It would be great if you could also mention any important tips or precautions that I should keep in mind while navigating this process. Thank you in advance for your help!