Data backup is topmost important that should be in your top-list plan. Plan your data what to backup and how to backup. Where you want to keep your data either in local USB External drive or cloud. Talk to your IT guy about your plan and try to get some sorts of knowledge from internet before talking with any professional. It will help you better understand about others plan.
Most of the time people are facing serious issues with there newly purchase computer or the computer they are using in home or office. It is found that users facing slow down performance of there PC just after download something or after watching movies. Sometimes they found the newly purchased computer given them hard time as its performance dramatically goes down. To get rid of such situation you need to physically clean up your computer and peripherals, update your program, apps, antivirus and Windows itself. Always backup your data through external device or cloud.