I don't know how it is on your server, but the best way to do things with randoms is to already have some people who've cleared the content to come help you. Try get to know some people who have cleared the content, they don't need to be friends of yours really, just ask them every now and then if they are up to spending 90 minutes helping you practice a floor with some randoms. You can tell them they don't need to teach anything or give advice if they don't want to, but that they need to be prepared for a lot of wipes to things they might consider stupid deaths.

Once you have some people willing to help you, use Party Finder for a learning X phase party while shouting in popular zones every 7-10 minutes that you're recruiting. It's best you do this on a kinda peak hour days after weekly reset. Weekend is great time for this but if your server is popular your Party Finder might be surrounded by a ton of messages so it will be hard to notice.

If you want a linkshell for PUGing Alexander, if you can't find one you might need to start one yourself.