For the “Team Synergy” achievement, your guild would need to contirbute enough gold to guild tasks in a week to complete all of your statues. This takes a total of about 15.5 million gold and is therefore limited to guilds with a lot of hardcore players or guilds that are willing to save up for several weeks and coordinate their donations.
There is an X-Box Guild looking to recruit players to earn the Team Synergy achievement right now:
For the “boogeyman” achievement, the requirement would change every week. If you go to the event screen from the map screen, you can see this week’s events. One of those will specify 6 levels of rewards and the number of event points required to receive them. For this week, to earn the achievement, you would need to defeat 1000 enemies in explore mode. Starting Monday, it will be something else.