So i was modding my 2ds trying to get custom firmware and I got to the part where you have to put your 2d/3ds to the oldest firmware and where it makes the screen all zoomed in and such but I couldn't get pass the next step because it kept messing up so like a dumbass I factory reset my 2ds and now I'm on the screen where it says to slide up the 3d slider but I have a 2ds, how can I bypass this would really appreciate help its been 2 years and I'm still trying
You used a horribly outdated guide. This is why you shouldn't follow video guides, there's no telling how outdated they may be and any time the methods change slightly an entirely new video needs to be made, which most people don't bother doing. Had you been using an up to date guide, you would not have needed to downgrade, and the newer methods are much safer.
The only guide you should be using nowadays is
http://3ds.hacks.guide as it's the most up to date.
You're either going to need a copy of Cubic Ninja and the tool mentioned by
@Chary, or a ntrboot compatible DS flashcart (a full list can be found here:
https://3ds.hacks.guide/ntrboot )