if you are not "tech-savvy" I recommend leaving RAID for another time, not right now. While RAID can be wonderful, if it is not set up correctly, you can lose everything instantly if a ransomware hits, if one of two HDs, if one or more HDs of multiple hard-drive RAID goes bad, you must know immediately how to correctly fix the problem - or you lose everything. When it works, RAID works great! If it develops a problem, one better know how to fix or else. Last thing, Lady Fitzgerald said it best: RAID is not a backup. I add: RAID is a perfect replication process, it is not a backup ('cause it is online 24/7-365). [Disclosure: the only thing I know about RAID -- it kills bugs dead!]
First of all, you do not necessarily need to be tech savvy to setup and use RAID...depending on what route you take. Yes, setting up software RAID might be on the more complex side. Hardware raid can also involve some work in certain cases, but you can also get RAID 1 hardware based drive enclosures that are very easy to setup. I have a RAID 1 hardware enclosure that was purely a matter of installing the drives and hooking up the enclosure to the computer. That is it. No more hard than getting a single drive enclosure and installing a drive and hooking it up other than I just had to install a second drive. So, it really depends on what path you go.
Second, I would disagree that RAID is not a backup. I would agree that some "flavors" of RAID are not backup. For example, RAID 0 is definitely not a backup in any way nor is it a replication process. RAID 1, OTOH, is effectively a backup in my opinion. After all, RAID 1 is a "replication process" as you said and technically a backup is at it root a "replication process". After all, a backup is effectively just a replication of your files. The key is that RAID 1 is a backup method that will not protect against all potential forms of data loss. But, then I would argue that RAID 1 is not that much different than having an external drive constantly attached to your computer that then has daily, scheduled backups run to that external drive. Both of those approaches (RAID 1 and constantly connected external hard drive) will not protect against something like ransomware as the files on the constantly connected external hard drive could be encrypted by ransomware just as easily as the mirror drive in a RAID 1 array. Yet, "backup purists" would consider one a backup and the other not. I kind of say BS.
To me, any method that duplicates data as a protection method against some type of potential data loss is a backup method. To me, this includes RAID array options that include some form of redundancy (i.e. allow for a drive to die and not lose data). Yes, this only really protects against a drive dying, but it is better than nothing and just as good as a constantly connected external backup drive for the most part (there are differences as a RAID 1 "duplication" is instantaneous, while a constantly connected external drive will not be "updated" until the scheduled run of the backup, so even if that backup is some sort of sync process, you have time before some file deletion or corrupted file gets synced...and if not a sync process but rather an image or similar, then it is dramatically different that how RAID 1 "backs up"). I personally use various RAID options as a first line backup. I also do other "backup purist" approaches as additional backup layers as well to help protection against other possible ways of losing data (i.e. accidental deletion, malware, natural disasters, etc).
The key is first to have some sort of backup. While "backup purists" don't consider RAID 1 as backup, it is way better than nothing. To me, it is better to have something rather than nothing. While there are better "only" options that RAID 1, I would rather someone have RAID 1 than nothing at all. And considering that "effort level" is typically a reason why people do not backup, using a hardware based RAID 1 enclosure that is super easy to setup and requires effectively no effort to maintain, it is a good option for those who do not want to expend any effort for backups to still have something. So, while I might prefer they do a more "backup purist" type option, I will not discourage someone from using RAID 1 if they currently do not have any backup system at all.
The second key is to know what your backup method's strengths and weaknesses are. Then you can decided if those weaknesses are such that you decide it is not a good backup method for you and you should switch to something else or if maybe is OK as a first layer but you need to add additional layers to your backup scheme. In my case, I know what the weakness of the various redundant RAID options I use are, so I add additional backup layers beyond any RAID option I use. But, all backup methods have a weakness. This is why the 3-2-1 approach tends to suggest different media and at least one off site backup...it "knows" that a single backup layer will have weaknesses, so it adds layers.
In the end, lots of people have their own biases about how to backup. For example, some people dismiss using optical discs as a backup method these days. Yes, it is more work, slow, and optical media can be potentially unreliable at times, but then it is better than nothing. My personal attitude is that I try not to let my personal biases shut down someone such that they then might not backup at all. Better that person backup to optical discs than not backup at all. For example, I personally do not like online backup services, but they work well for other people. So, I don't let my dislike of online backup services lead me to tell others not to use them. That is a decision that they need to make themselves (I might offer why I don't like them so that they can factor that into their decision if they want) and if it works for them, then great. In the end, what works for me might not work for someone else. And what works for someone else, might not work for me.