My husband and I are thinking if we should just combine our baby's baptism and first birthday celebration. Do you think that will be fine?

I would actually go with combining the two. Practicality is still best especially because at this age, you would be spending a lot for your little one's necessities. Having to save the money that you will be spending to say your baby's baptism would really mean a lot. I know some of my friends who really tried to have the baptism and birthday celebration separately but then were very regretful afterwards because of the thought of the amount of money they could have saved up.