Your first layer is failing because the bed isn't actually clean
Hobby FDM owners burn hours chasing Z-offset when the real problem is film on the bed.
Wipe the PEI or glass with warm dish soap, not just IPA. IPA spreads oils. Soap cuts them.
Then:
Heat the bed to print temp and re-wipe once.
Run a 5-line skirt, not a full brim, and watch the first line only.
If it looks like spaghetti, drop Z 0.05mm. If it looks like a pancake, raise it.
Most Ender/Prusa prop prints fail in that first 30 seconds. Fix the bed, then touch offset. Not the other way around.