And how will I understand it is filled , there is a narrow hall and larger diameter pouring gate.
Just pour into the center hole
Do I need to fill untill the top ?
Just prepare the stated capacity: 290ml (I use 300ml)
How will I prevent bubbles ? Do I need to agitate just after pour ?
Fill (with dev). Start timer. Put the cap firmly in place. Invert once. Tap the bottom of tank on table 2-3 times; this is supposed to dislodge bubbles. Invert 2-3 more times, tap again.
Do I need to wet the negatives before the developer been poured ?
Some people do. I don't. If it works without, why bother?
One more thing: make sure all liquids (dev, stop, fix, wash) are at the same temperature +/-2C. Otherwise unpleasant things may happen to your film.
Wash: google search for Ilford method.
Before hanging to dry: wetting agent at supplier's recommended dilution for 1 min, use distilled water (sold in drugstores for steam irons, cheap). Hang film in a dust-free place, no wind, no sun. Do NOT wipe film.
Good luck and keep us posted with your results