Presbyterians have official confessions of faith. For the PCUSA you should look at the Confession of 1967 and probably the Brief Statement of the Reformed Faith. The web site would be
https://www.presbyterianmission.org/. (There's a pcusa.org, but it has become almost useless. Not sure why they moved the content to a different website.) Conservative Presbyterians use the Westminster Confession, and mostly they're pretty serious about it. Note that there are denominations called "Reformed" that are similar to Presbyterians, with beliefs probably somewhere between the PCUSA and conservative Presbyterian groups.
Methodists believe mostly the same thing the PCUSA does, but don't have a collection of confessional statements. Their web site has statements on specific issues. Note that there are conservative Wesleyan denominations, if you're trying to avoid mainline denominations.
Also consider Lutherans and Anglicans, if you're interested in more liturgical denominations. Again, their mainstream denominations are similar to the PCUSA. But they also have conservative offshoots. The LCMS follows the Book of Concord, and has good information on their web site. I'm not sure of the conservative Episcopal.
The mainline denominations differ a lot among congregations. While the leadership have a pretty coherent theology and ethics, there are conservative congregations. The conservative denominations tend to require uniformity.
Most of these groups have web sites that will point to any official confessions and give you a pretty good idea of their priorities and ministry. However some of the mainline churches haven't been writing new confessions, so their apparently authoritative documents may not show what they actually believe. But generally you can still get a good idea from the web sites.