This is awfully broad. There are basically three approaches:
- choose a schedule (on your own or in consultation with the group), announce it well in advance, and expect people to schedule around it. Every other Wednesday, period. This works great when it's important enough that people will decline other opportunities because they have your event already scheduled. It also helps if you can get by with less than full attendance.
- Negotiate the "best" time for each occasion, using the various apps and web sites for this purpose (the field changes constantly, so I won't recommend one) and announce the date with very short notice, knowing that it's free for everyone. This can be annoying for the other people in your team's life who literally don't know if their spouse/partner/parent/child/roommate are busy Tuesday night or Wednesday night until the voting is finished. It also has trouble if one person's no-go date is consistently getting chosen by the rest of the group, and there's worry about favouritism and exclusion. It's most useful for a group that has a lot of other variation in their schedules, so they aren't consistently free Wednesdays, for example.
- Set up a rota of people who choose the date. They can choose however they like, including negotiating with everyone else, arbitrarily setting a day, or whatever. The idea here is that it will work out fair in the end. Some days Steve will choose a date that excludes Bill, but Bill will get a chance to choose a date so will not be missing too many events. It also shares the workload, which can be significant, of chasing people to update their calendars or submit their votes or whatever.
If you are a small team that needs 100% attendance and doesn't have a lot of "I can do it Wednesday but only if it's at my house, or I can do it Tuesday anywhere" kind of high-thinking constraints, then the negotiating can work. But if you can get by missing one or two, I strongly recommend just picking a pattern and sticking to it. It can be "every Wednesday night", or "the 5th, 10th, 15th, 20th, 25th and 30th of every month" (that one wanders around on what weekday it hits) or a set of dates chosen by dice roll, as long as it's well known and the understanding is that being on this team means making these dates.