Samsung a71 virus detected so uh, i just went onto a website, and I apparently have 4 viruses on my phone, it said &quot;Your sim card has been damaged by a virus!&quot; I dont know if this is fr and I'm only 14, but i know when not to click on something stupid. But I have to ask, is this real? I know how to deal with it if it IS true, but it is weird. It says my sim card is already 48% damaged.
The comments on your question already cleared things for you. It is a scam. If a website or an app suddenly or  ever claims that something is wrong with your device, its accessories, its OS, a web account, your bank account, you can be damn well sure that the other  party is trying to scam you.
10/10 times these scams appear as ads, so using an adblocker for both your web browser and and your device is suggested. I use Ublock Origin addon (on Firefox for Android) which greatly helps in reducing ads nonsense when browsing. To stop nonsense ads on Android apps I use AdAway (you can also use Blockada) adblocker app. Some folks give moral reasons not to use adblockers but I keep security, privacy and web sanity over morality. You are on your own with morality here.
In a browser, 9/10 times these ads are able to load through javascripts, often third-party scripts. Using a solution which blocks at least third-party javascripts is recommended to everyone for browsing the web with sanity. I use NoScript addon (on Firefox for Android).
You also need to know about WAP billing frauds (you click something on some [often] not-so-popular webpage, and guess what XY amount of money is automatically deducted by your carrier. You apparently gets subscribed to some XYZ value-added service!). WAP billing frauds are facilitated by third-party javascripts.
The list can go on but it is best that at this age you spend a couple of hours to learn about privacy and security on the web, Android or whatever OS your mobile and PC are using, on at least a monthly basis. What you would learn would be far better than a quick fix I have suggested.