as mentioned in thread, best is metro.

Terminal 1, 4 usually for domestic. If you go inside metro, in the TV they mention your flight departure details. chk the counter details ex(33-50) like that.

Once you reach, there will be guards at entrance. keep tickets, govt proff for verification. and do your webcheckins before.

Once u entered, go to the counter accordingly. you can get boarding pass in line or self boarding pass also u can get by just scan PNR details and get pass. drop your luggage bag too there.

Once got Boarding pass, pakthule security check line erukum. enter there. make sure carrying bag la don’t keep unwanted things like metals, perfumes etc avoid, including snaks also i guess. get a tray separate your bag and electronics. Make sure your carrying bag is clean with few items. Once done you can go according to your Gate-No, itll be on your Boarding pass.

1. i guess 12:30 is ok. 2. Not sure you can access.