NYU subscribes to the massive database:U.K. Parliamentary Papers. You can find more detailed information at the research guide United Kingdom: The Parliaments: Parliamentary Resources​ at https://guides.nyu.edu/parliament .
Below are brief descriptions of the four currently functioning national legislative bodies, with links to their websites. [Any quotations are from the body's own web-pages.]
This is the legislative body of the United Kingdom, including its overseas territory, and is located in London's Palace of Westminster.
The Parliament is properly known as the Parliament of United Kingdom of Great Britain and Northern Ireland. In 1707 the Treaty of Union between England and Scotland created the Parliament of Great Britain from the Parliament of England and added Scottish members to both Houses. The 1800 Act of Union created the Parliament of Great Britain and Ireland, abolished the existing Parliament of Ireland, and added Irish members to both houses. In 1920 the government of Ireland Act created two parliaments in Ireland, Northern Ireland and Southern Ireland, while reducing Irish representation in Westminster. In 1922 the independent Irish Free State was created and in 1927 the name of Parliament was officially changed to the current Parliament of United Kingdom of Great Britain and Northern Ireland.
Parliament is divided into two Houses: the House of Commons whose members are elected and the House of Lords, which are not. Members of the House of Lords are of two types, bishops from the Church of England (Spiritual) and those from the Peerage (now appointed titles). According to the Parliament website the Commons is a "Democratically elected house, makes laws and checks the work of Government and the Lords is "A forum of expertise, making laws and providing scrutiny of Government." There are 550 members of the House of Commons (Members of Parliament, or MPs) and 786 Lords.
The Parliament of Northern Ireland existed from 1920 until 1972, with 52 members of Commons and 26 members of a Senate. Suspended in 1972 and then abolished in 1973, the Parliament of Northern Ireland was replaced with the Northern Ireland Assembly with 108 members.According to its website "The Northern Ireland Assembly is the devolved legislature for Northern Ireland. It is responsible for making laws on transferred matters in Northern Ireland and for scrutinizing the work of Ministers and Government Departments. The Assembly sits at Parliament Buildings Stormont Estate, in Belfast. Members meet to debate issues; question Ministers; and make laws for the benefit of people in Northern Ireland. Each MLA represents her or his constituency, and there are 6 MLAs for each constituency."
In 1999 the Scottish Parliament (or Pàrlamaid na h-Alba) was created with 129 members. "Scotland was granted devolution by the passing of the Scotland Act in 1998 which means that Scotland has a parliament with ‘devolved’ powers within the United Kingdom. Any powers which remain with the UK Parliament at Westminster are reserved. Reserved matters were set out in Schedule 5 of the Scotland Act. A basic breakdown is given below. Essentially the powers of the Scottish Parliament are set out by what it does not have legislative competence in rather than in what it can do.Devolved powers: Matters such as education, health and prisons, which used to be dealt with by the Parliament at Westminster, are now decided in Scotland. Reserved powers: Decisions (mostly about matters with a UK or international impact) are reserved and dealt with at Westminster."
There is a website Records of the Parliaments of Scotland before the Act of Union here: https://www.rps.ac.uk/ : "The Records of the Parliaments of Scotland to 1707 (RPS) is a fully searchable database containing the proceedings of the Scottish parliament from the first surviving act of 1235 to the union of 1707. The culmination of over ten years’ work by researchers from the Scottish Parliament Project based in the School of History at the University of St Andrews, the online edition seeks to make this key historical source freely available to all in a technologically advanced and user-friendly format."
1999 was also the founding and first meeting of National Assembly for Wales (or Cynulliad Cenedlaethol Cymru/span>), which has members. The National Assembly for Wales is "the democratically elected body that represents the interests of Wales and its people, makes laws for Wales, and holds the Welsh government to account."