So I want some advice on how to do what i want.

[Tony Vargas]

I want magic items coming out of the Wazoo! I just love tons and tons of magic items! I don't want them to be rare and mysterious but instead to rain down all over the place!
I would just like some help with how to do what I want(tons of magic items) in D&D 5E.

5e's magic items are designed with the idea that just one or two of them would be really special and make a character 'just better' than one without a magic item.

Thing is, you don't have to use 'em. You can just make up cool magic items out of the blue, that /don't/ eff up the game too much.

I really hate the spell limits. High level wizards and clerics getting so few spells is utter crud to me. Add to that legendary actions and auto making saves and it's just a nasty mess. What if i just use the old spell progression?

Which 'old' spell progression? The 1e progression started with fewer spells than you get in 5e at very low level, for instance. So, no, it probably wouldn't be a big deal...

Plus, if you have a world where magic items that duplicate spell effects are commonplace, spell casters become a lot less special, anyway. Throwing a fireball is a major ability in a low-magic-item setting, but if everyone and his second cousin has a necklace of fireballs, it's no big deal, so let 'em throw all the fireballs they want, it'll only be an advantage when everyone else is out of de-facto grenades. Turning invisible is enough to sneak into a king's castle in a world where magic is barely even believed in, in one where elven cloak & boots are standard-issue to military scouts, and invisibility potions are used for school-boy pranks, OTOH, it's going to run up against all sorts of well-prepared counter measures.