Hi Isabella,
as a Guildleader of a TOP50 guild i think there are a lot of points to keep a guild running.
1. Use an Communication App like Line, Band etc. to keep in contact with your players. With these Apps you can share Screens or Videos to help other Players, organise you GW and create a bond between your guildmates.
2. Keep in mind what a guild is realy all about - compete with other guilds in Guild Wars. Thats one of the hard points in running a guild. Since GWs are on WE most players have other duties with their families. You have to motivate them to help the guild by spending time on DH5 to achive a goal in GW. Thats not easy because of the crappy rewards you get for spending a WE playing DH5 in 18-20 GWs. Without the experience of playing GW together your guild will fall apart - because GW is the only aspect of the game were your guild works together.
3. Help other Players - besides of bonding for GW you should share your tipps how to play the game. Help them to build stronger Strongholds, tell them what Armor/Weapon/Skill works best in a Set etc.
4. Motivate your players - DH5 is full of ups and downs. Sometimes your SH has no defs, you pull some chests and do not find the disired item, you cannot beat a SH etc. Your guild is a platform to share these ups and downs with other people. To see your not the only one having problems helps.
These are some key points, there are a lot more. But enough for today.
Bigdragon
Please forgive any misspellings - i'm not an native speaker

p.s.: Guild Tournament would be another place where your Guild could play together. But since the recent changes european players can not participate (ends 4 o clock in the morning) and usually only 3-5 guilds fight for TOP3.