Hi Senecka. I run an 18+ social/casual raiding Horde guild on the connected realms of Lightbringer/Mazrigos.
We raid twice a week, Wednesday starting at 21:00 ST for 2½ hours, Friday starting and finishing 30 minutes later. We raid only normal and casual level raids (currently part way through heroic Sanctum) - only ever generally dabbling a little in mythic at the end of an expansion if we’re bored, and only for fun.
We also have M+ mentored/low and slow (untimed) organised groups on a Monday evening for people to learn tactics/routes, etc, alongside various levels of M+ organised on an ad-hoc basis throughout the week. We’re currently in the process of having higher level M+ also getting organised in a similar manner, with the aim of getting people up to and beyond 15-20+.
We aren’t hardcore by any means, we don’t all raid, or do M+. Events go up on the calendar, or shouts go out in guild/discord for groups, and people sign up/volunteer as and when.
Most of us have families, work and other stuff going on irl, so play wow to unwind, so we don’t stress if things don’t happen, we just find something else to do. Which probably explains the massive number of alts, achievement collectors and pet battlers 
If you’d like to learn more about us, please visit our realm post: [H] Dark Wolves - 18+, Casual Normal/Heroic raiding, M+ & Social
I wish you all the best finding a guild. 