There are 3 entries on family search - 2 are submitted (meaning others are also researching your man). The final one is extracted from parish records, so it gives the actual place of baptism and the baptism date rather than birth date.
DAVID COX Christening: 10 MAY 1783 St John, Deritend And Bordesley, Warwick, England
Father: JOSEPH COX Mother: FRANCES
Batch C069811 1699 - 1869 Film 0588406
If you click on the batch number and then look for children with the name cox and parents Joseph and Frances, you will find 2 siblings Maria(1782) and your David (1783).
To check if there are any siblings born in a different parish, you can do a parent search. Put Joseph Cox in father, Frances in mother and then select the dates and location you wish to check. (I didn't find any others).
There is also the parents marriage on the IGI
JOSEPH COX Spouse: FRANCES WALFORD 25 NOV 1779 Aston Juxta Birmingham, Warwick, England
Batch M011682 1754 - 1813 Film 0919794-796
Trish