It is mostly for Guild Leaders. Regular guildies, even VLs, can't do much of anything.
Only things that they can do (and should do) is donate to Sentinels. You get one donation per hour and cap of 10 donations, so make sure you get everyone in guild doing it. You might want to agree which sentinels to donate to, since some of them need so much donation that it would take group effort to level them.
Either way, watch the last fight (only GL can start fights and you can only see last one) to see where your weak spots are, and ask your GL to fix them. Also, make sure your Gl gets shop to L3 so you can buy all the stuff which is for sale.
What would help is to have some idea how to make guild base and how to arrange sentinels, and which to level 1st. I haven't seen the video (I find 25 minutes long videos to be awful horrible terrible no good useless worthless ineffective inadequate bad no good ways to write guides that are not inherently visual in nature like ID clears), so maybe it covers that subject.
It so, hopefully someone will write it up.