I have a main crystal report (2008) with data in details a with page header:
Page Header: id last first mi date1 date2
details a:     id last first mi date1 date2

I added details b to insert the subreport:
details b:    <subreport name> ...has similar data/titles; uses param from main report

When I preview my report, I'm seeing one person (row) per page, and I cancel the preview after it gets to 1000 pages.
Before I added the subreport I had maybe 8 pages of data, with the full page filling up with rows, with maybe a total of 50 per page I'm guessing.

I'm trying to figure out how to get the main report data to show on it's 8 pages or so, and then in the following page (or after the end of main data), show the subreport data. Subreport data is only a few rows total.

I'm not really sure how to do groups. I tried adding a group to my main report, and order by id, but couldn't figure out how to get a group2 with the details b data. I'm not sure if that would fix it or not. Right now my report shows

page header
group header 1 (hidden)
group header 2 (not sure how to move it so it has detailsb)
details a <data>
details b <subreport>
group footer 2
group footer 1

I tried googling the issue but can't find a solution or similar problem.

If you want to have the sub-report show after the main report data, then I believe you should have the sub-report in the report footer section.