Hi
There are almost no census before 1841. For some places you might find one from 1831 or even 1821, but they have a lot less information and very few have survived.
If you look at the 1851 entry for George, the birthplace clearly has a letter that continues down below the line ((totally forget the proper name for that!) and it is actually Badg(e)worth, Gloucestershire.
So you could start by searching using the surname and that place of birth.
Up pops a couple William and Elizabeth, surname spelling varies a bit:
1841
William Collingham 35
Elizabeth Collingham 35
Mary Collingham 12
Henry Collingham 10
and Henry's baptism gives their address as Little Witcomb Badgworth, but he is baptised at Great Witcomb. Whereas Mary (Ann) was baptised at Badgworth.
Ancestry has a baptism record:
Name: William Collinburn
Event Type: Baptism
Baptism Date: 13 Oct 1799
Baptism Place: Badgeworth, Gloucestershire, England
Parish as it Appears: Badgeworth
Phillimore Ecclesiastical Parish Map:
View this parish
Father: John Collinburn
Mother: Amey Collinburn
and there is this record there too
Name: George Collin
Event Type: Baptism
Baptism Date: 6 Feb 1802
Baptism Place: Badgeworth , Gloucestershire , England
Phillimore Ecclesiastical Parish Map:
View this parish
Father: John Collin
Mother: Amey Collin
but if you look at the image then the surname is longer and almost certainly Collinbourn or something like that. And the year is 1803. So that seems to be a good fit for your George.
In general, once you are back beyond the census records then you have to rely on baptisms, marriages and burials. If you are lucky then you might find a will, even for quite poor people, and find the names of children or siblings. Unmarried great aunts can be wonderful if they mention all their relatives! There are also some other parish records, often sourced as the "parish chest". But I've never looked at those myself.
Be open minded about spelling and use * in searches. And look at the geography to see what parishes are nearby because rural people moved around and changed parish sometimes. And some also chose non-conformist places instead of the parish church.
https://www.genuki.org.uk/big/eng/GLS/Parishes#index1 is a very good site for parishes and stuff.