How to improve very poor quality prints on my Ender 3
i would suggest to start with something simpler

there are many test objects to print and see the results
please take a look here

the idea is to recognise issues (one by one or at least the most basic) and point them and eliminate them directly

looking at your printout i could of course suggest many things
but it would be better to make this process more clear... for you

so you could manage it on your own

to be somehow constructive

i would say there are 3 main issues on the picture you've presented


HE temperature
printing speed
not-so-stiff printer construction (or belt tension)


print test cube and show your results so we can go further