Conjugate addition vs Electrophilic addition
Grignards unless modified with Cu(I) salts add 1,2 not 1,4 so the EtMgBr will add to the ketone to give the t-alcohol and leaving the double bond intact. 

Consider then the HCl step - if it is strong enough to protonate the double bond leading to Cl addition then it will protonate the t-alcohol in preference leading to elimination or t-Cl formation. So the answer is to do the reaction on the double bond first then the Grignard addition. Protonation will occcur at the carbonyl oxygen but you have to remember that the double bond is in conjugation with the carbonyl system. This polarises the double bond, leading to Cl- attack at the end of the system.

The Grignard is more nucleophile than base so you will get majority addition to the ketone though some deprotonation/elimination may occur depending on the reaction conditions.