Before you ask for baptism details you need to know the names of the two parties. So first you have to find the marriage of Joseph Barefoot and Ann. As it's not on the IGI at
www.familysearch.org hopefully someone reading this will check to see if the marriage is on Boyds Marriage Index. Once you have Ann's maiden name you can check the IGI to see if her baptism appears (there's no Joseph Barefoot on the IGI in Cambs that fits his likely birth period). You then need a look up to see if the marriage entry in the appropriate parish register mentions the parishes of residence of the couple.
(if you follow the link on the previous word, you will learn "As of today they are giving a 90 Day, Get Laid Guarantee !". Egg Marketing Board promotion? I think not! Or "you will probably have Sex within 1 or 2 days". Chance would be a fine thing. But is this really what I want to know on RootsChat? What has my passion for genealogy got to do with me having sex within the next 48 hours? I am not a prude, nor am I against advertising on RootsChat. But some of these links are demeaning to RootsChat)
You should also be aware that there are two types of entry on the IGI - extractions from parish registers, which are reliable; and member submissions which vary in reliability from well researched to pure fiction. The Swaffham Bulbeck Barefoot entries are all member submissions, so MUST be checked, but despite that they look well researched. Before trying to go further back you really need to double check the entries that Meliora found, firstly to see if they actually exist in the parish register, and secondly, on the assumption that they are real, to see if there is any additional information which might give you clues and which might help to fill in your knowledge of the family eg occupation, witnesses to marriages etc. (John's christening is shown as 1803 not 1802). You say Samson was christened on 5 Apr 1839 whereas the IGI Member submissions say 5 Apr 1840 - which if you're right (and his census ages point to 1839) is why I say member submissions should always be checked.
You asked for advice - slow down and check each generation before moving onto the next. That way you stand less chance of researching someone else's tree!
David