Randy,
Statutory birth, death and marriage registration (in some jurisdictions called Vital Records) only started in Ireland in 1864, save for non RC marriages which were recorded from 1845 onwards. So you probably won’t find statutory birth, death or marriage certificates in Ireland for this family. For earlier years you usually need to rely on church records, where they exist. Not all churches have records for that period and not all are on-line.
As you say, Church of Scotland & Presbyterian is the same thing. You do occasionally come across Church of Scotland, in Irish censuses, but mainly they used the term Presbyterian. (With a Presbyterian living in Co Down and a Scottish name like Campbell, you can probably safely assume the family came over from Scotland in the 1600s).
For Presbyterians the churches usually hold the originals but there are also copies in PRONI, the public record office, in Belfast. A personal visit is required to access them. Access to the records there is free. This link explains what records exist, parish by parish:
https://www.nidirect.gov.uk/publications/proni-guide-church-records
If you are unable to go yourself, you could employ a researcher. Researchers in the PRONI area: http://sgni.net
There are 6 Presbyterian churches in Bangor but none has any records before 1829, so you may struggle to get back very far. However you may find the baptisms of the children born post 1829. If you find any baptisms you may get the family townland and if so I can have another look to see if I can find anything more. If Patrick had 27 acres of land in the 1820s or 1830s he ought to be in the tithe applotment records (which were compiled for land taxation purposes). These are the only 3 I can find anywhere in Co Down, in the parishes of Inch, Annaclone & Tullylish. If you don’t find the family in any Bangor records it might be worth searching the Presbyterian records for those 3 parishes.
Campbell, Pat.-Townland: Ballyrenan Year: 1825-Inch-Down
Campbell, Patrick-Townland : Ballysheal Year: 1833-Annaclone-Down
Campbell, Patrick-Townland: Clare Year: 1834-Tullylish-Down
Your Patrick making linen would be fairly standard. Most farmers in Ulster grew a bit of flax and then got their labourers to weave it into linen on hand loom weaving machines like the ones still used in the Outer Hebrides to make Harris Tweed. (Most Irish linen was made in Ulster). By the mid 1800s water powered factories were springing up in Belfast and other towns in Ulster which made it faster and often to a better standard. This gradually made the home weaving industry uneconomic.
The land around Bangor is good quality and a farmer with 27 acres there should have had a fairly comfortable life.
