There's probably loads of these out on the interweb, but I'm thoroughly enjoying going through an 1877 Hymns Ancient & Modern freely downloadable from https://archive.org/details/hymnsancient77chur.
They're great for practising sight-reading, phrasing, tone and intonation. And as I've said elsewhere, once I've played through a tune a few times, I particularly like playing it by ear, from memory, starting on a random note without thinking about what key that puts it into. This 'playing the interval' rather than the note helps develop 'intuitive' pitching and fingering, transposition skills and a feel for the underlying harmonies.
Many tunes are non-modulating, and these can be viewed as Step 1, basic major and minor scale harmonies.
Step 2 are (usually more interesting) tunes including the standard modulations into the 'uplifting' dominant, 'reflective' subdominant or 'subdued' relative minor. Lots of these, but hymns #2, #14, #222 (tonic-dominant); #43(2),#119 (tonic-subdominant); and #5, #47 (major-relative minor) are a sample to learn the distinctive feel of these harmonies and the adjustments that come with them.
Step 3 modulations are the wyrd and unusual! Try the following. Most of them can be quite tricky if you pick the 'wrong' starting note! Not even 100% sure of the 'true' home key of some of them (#98(1) in particular):
#25 - tonic-supertonic
#17(1) - tonic-major mediant
#29, #79 - tonic-minor mediant (relative major)
#142 - tonic-major submediant
#98(1) - tonic(dorian)-subtonic
#76 - subtonic(dorian)-tonic-minor mediant(ionian-aeolian)-tonic