1) Check the coolant reservoir, the white bottle. It should have the coolant upto the max level. That is the right way to check the coolant level. If not, refer to the owners manual and add only the mentioned coolant.
Btw the coolant from factory is slightly below the "full" mark, which is absolutely normal.
2) Service as in mechanical service, or the car washing? Mechanical service is just the oil, oil filter, and air filter. Nothing else atleast till 25k km.
For car washing, don't use water to wash the engine, the the normal service should be good.
3) Use 5w20 or 5w30 only. They're the better options. Any brand should do as long as you keep the change intervals low, under 3k/4k km.
4)if you've disabled ctba through the instrument cluster the light is there as an indication to let you know that.. and will stay disabled until turned back on. . I also favour keeping it off. Our people drive so close, keh phir apna bumper tou gaya.
Hope that answers you