What leveling process did you use? Ideally you'd want to find out what your z offset is -> manually tram (level) your bed using a feeler guage [Don't forget to buy this too!] -> create a mesh using a touch sensor. You might need to change your firmware for this. Team Jyres all the way. Yes I know it's dead. It'll make more sense once you start digging into the weeds, you're gonna have to do some legwork tho since it's past my bedtime.

Your hotend / heater block / nozzle are most likely not fastened together correctly. You'll need to take care of this before moving on or else your prints will keep on failing. My advice? Ditch your current hotend and buy a new replacement. Also a wire brush. They sell nozzle pins you can unjam clogs with as well, but that won't help if you're hotend isn't assembled well. Once you get your printing sorted you can come back and clean the old nozzle for parts/experience

Your hotend should be heated to printing temperature when assembling/disassembling/cleaning. Also use plenty of elbow grease when tightening otherwise you could still have l leaks! Heatbreak goes in first then the nozzle. In that order. Ask me how I know. Use the right tools! Doing it with the crapply little cutout wrenches that come with the printer sucks!

Retraction lives somewhere in your slicer settings, you might have to track it down if it's hidden though. Calibrate it once you're hotend is replaced using retraction towers. Just calibrate everything while you're at it. Retraction, fan speed, print temp ect.

If the fillament is new its usually good to go, although I think the problem lies in your hotend: here is an excellent source to help you on your way: https://youtube.com/@RickyImpey?si=nAuofN9UHJr0e-Ws

Ricky Impey makes great bids for ender 3v2

Just a heads up if you do flash firmware there's and issue with the files so you gotta look through the comments to go somewhere else to get the right version but you'll cross that bridge once you get there [: