Hi Tony
I'll have a go at some answers - no doubt someone will correct me if I am wrong about anything.
Until 1753 it was possible to marry pretty much anywhere in England, as long as a clergyman performed the ceremony. This led to some irregular marriages and the 1753 Marriage Act made it so that all legal marriages had to take place in a Church of England church and parental permission was required if bride or groom were under 21. There was an exemption to this Act for Jews and Quakers, but it did mean that Catholics had to marry in a C of E church if it was to be legal, even though baptisms and burials could be in an RC church. No doubt many Catholics would marry in two places because of this, though I think that some only had a Catholic marriage even though this would have no legal status.
In 1836 there was a new Act which permitted civil marriages too, and also marriage in religious buildings that had been registered - but still only if a Registrar was present.
After late in 1837 (not sure of the date) civil records were introduced. Initially birth registrations were voluntary I think (not sure about that) but soon it was required to register a birth within six weeks. Similarly deaths were registered, and also marriages. These would be at the local registry office, based on the address of the event.
Before 1837 there were only church or chapel records. I've no RC people in my family so I've seen little of those records (happily since they tend to be in Latin!) and non-conformist records can vary a lot. C of E records were kept in the Church as parish records, until latterly when most have been sent to the local Archives. It was also required to submit a copy of parish records to the local bishop, and they are also usually to be found in the Archives now - but confusingly they may not be the same one as the parish records, for historical reasons.
You might also come across marriage banns. In theory they would be read for four consecutive Sundays in the church where the marriage was to take place, but also in the parish church of the groom and bride if different. They tend not to give much information but are sometimes all that is available online.
Before 1837 you will probably only get the names of bride and groom, their age (full if over 21) and the name of their parish. Plus the names of two witnesses who may be family members or not - good to compare witnesses to other marriages at about the same time, often it was a church warden or somebody like that.
After 1837 you should get names and ages, occupation and address (sometimes a convenient address to avoid paying for extra sets of banns to be read), the name and occupation of the fathers and the names of the two witnesses.
Here is Bridget's, taken from
http://www.lan-opc.org.uk/Search/indexp.htmlMarriage: 3 Feb 1834 St John, Preston, Lancashire, England
John Woodcock - (X), Bachelor, this Parish
Bridget Crook - (X), Spinster, this Parish
Witness: Lewis Crook; Margaret Woodcock, (X)
Married by Banns by: Thos. Clark Curate
Register: Marriages 1833 - 1837, Page 38, Entry 112
Source: LDS Film 94015
You say that you found William's baptism on that site, but I am concerned that he might belong to this couple
Marriage: 7 Jul 1801 St Andrew, Leyland, Lancashire, England
Thomas Crook - (X), Weaver, Leyland
Ellen Gorton - (X), Spinster, Leyland
Witness: Laurence Ainsworth; Nicholas Plaskett
Married by Banns by: Thomas Rebanks Curate
Register: Marriages 1793 - 1812, Page 117, Entry 469
Source: LDS Film 93952
It is hard to know, but I don't see why your Thomas and El(l)en would baptise him in a C of E church.
I can see a tree on Ancestry that has this couple attached to William and Bridget
Marriage: 1 Nov 1810 St John, Preston, Lancashire, England
Thomas Crook - (X), this parish
Ellen Hodgkinson - (X), this parish
Witness: Mary Crook, (X); Thomas Crook, (X)
Married by Banns by: James Penny Vicar
Register: Marriages 1805 - 1812, Page 207, Entry 828
Source: LDS Film 94013
Have you found RC baptisms for any of the children? Are they all at St Joseph's?
Finally, this is a useful site for seeing which churches were around the area
https://www.genuki.org.uk/big/eng/LAN/Chorley