In terms of the minutes, there is a legal requirement under section 228 of the Local Government Act 1972 to make available to any elector the minutes of any meeting at any reasonable time of day. https://www.legislation.gov.uk/ukpga/1972/70/section/228?view=plain
Any obstruction can result in a fine not exceeding £200 on conviction.
Because of this, it's easier to just publish the minutes on the website rather than have the Parish Office bombarded with requests when "something of particular interest" is passed. And it avoids the Parish Office having to be open every day if you only have part-time/flexi-time staff.
NALC's Legal Topic Note 5E (last updated in November 2021, but the same wording can be found in the 2018 and 2016 versions) confirms that this includes the decisions taken in any "closed session" (i.e. excluding the public) part of the meeting.
The meeting papers, if deemed confidential, should not be attached to the minutes. A reference should be made to them in the minutes though, such as "The Council considered the XYZ report before resolving the matter". I don't believe there is any requirement to attach any other papers even if not "confidential", although if they aren't confidential, there's no reason not to publish them and it shows a level of openness and transparency to publish them.
I also believe that there is a similar legal requirement to publish agendas for most meetings - Certainly Full and Committee meetings while Sub-Committee meetings and working groups are down to the terms of reference for those groupings. Ideally, they should be as open as possible for the public to witness, but if the Sub-Committee or working group is purely advisory in nature (i.e. has no authority to spend money), then anything they "decide" is always brought back to a Committee (which is required to publish an agenda for meetings) to be discussed/reported anyway. If there's any delegated authority to spend money by a sub-committee or working group, it's best practice that typical Full Council rules should be applied to the terms of reference. This would mean publishing an agenda in a public place, giving the 3 clear days notice, holding the meeting in a suitable venue etc etc