To change the font color to black on your page, add this to your extra.less template (Admin Panel > Appearance > Styles > [Your Style] > Templates > extra.less):
.p-body .block-body .bbWrapper {
color: #000000 !important;
}
If you only want it on that specific page (not site-wide), you can target it more precisely using the page's unique node ID. For example, if your page node is "rules", it would be:
.node--id-rules .block-body .bbWrapper {
color: #000000 !important;
}
You can find the node ID in your Admin Panel under Setup > Nodes — it's the URL portion listed next to the page.
As for the general tidy-up, could you share a bit more about what exactly you'd like changed? For instance: spacing, alignment, removing certain elements, adjusting the width? Happy to help with the specific CSS once I know what you're after.