If you're talking vaccines, and I assume you are, talk to reputable producers in your area and/or vet about what's needed there, what others are vaccinating against, and when.
How old is calf? Is it weaned?
We never vaccinated newborn calves. We vaccinated their mothers so the immunity would be passed on through the colostrum. Calves were vaccinated at about 1-2 months of age when we branded. As far as the vaccine we used, we used Bovishield Gold, and Scourgard 3.
Born on your place and nursing the cow, unless you're selenium deficient just leave it alone unless you have had a problem with early calf illness in the past. Better to vaccinate the cow and let her do the job of immunizing the calf.
Better still, for the sake of the animals in your care and your bank balance, buy a good book on animal husbandry and do some reading to get to grips with the basics. Not only will you be better equipped to deal with the challenges as they arise, but you'll also be better able to distinguish between good advice and BS on internet discussion forums.
I know a lot of people don't do it, but if I lost 2 calves, the vet would be working on why. Have you talked to your vet? Has anybody else in your area lost calves? I'd be thinking about a necropsy to find out what happened to keep it from happening in the rest of your calf crop.