Backing up your files
In terms of backing up the most vital files, it is not necessary to have many duplications of them. You had better stick to your mind that the cloud copies may be highly vulnerable to data loss and destruction and your external hard drives may not be able to survive if there is an attack caused by a fire, flood or robbery.
The first option to do is having backup utilities integrated into Windows and mac operating system, which make use of external drives linked to your computer. With Windows, you have received File History, which you can get through Update and Security and Backup in Settings. On Mac Operating System, there is Time Machine, which is available through Time Machine in System Preference.
If you have purchased an external disk drive, it may already have some backup software and there are a lot of third party tools on the market, including free ones like Cobain Backup to paid options like Acronis True Image 2020, which is integrated with many features and offerings. Some other programs, such as Carbon Copy Cloner, are capable of setting up backup drives that you can boot in order to back up your files.
When it comes to local backups, which are similar to main computer, another option is to make an investment into a Network Attached Storage device, which is an external drive by which you can link through your router instead of a cable. The benefit of doing that is that this kind of drive can be achieved from all the devices in your home, or over the web as well. However, accessing these drives may take a longer time.
These kinds of drives have all the software that you may need to get started and are an ideal option for the paranoid. You should get one with two or more disk drive bays so that you can have duplications of your original drive updated automatically when you work. If one may fail, you can have another same one to survive.