A lot of the toys from SL are locked behind a lvl 48 barrier. Only things I can think of are some Torghast items and transmog/mount farming as covenants aren’t really a thing at 20. A lot of what you prioritize comes down to what you’re after, tmog, mounts, toys, etc. one thing I’d recommend is only focusing on buying what costs over 1k gold. You can make gold without a sub, albeit slower, but you can’t hold over 1k before unloading in your warbank. I wouldn’t focus on too many reps with only a month. Frozen arms of a hero would be good to grab some of if you’re interested in garrison stuff. If you’re using gems, one of the best things to do would be to get revitalizing doublets as 20s can’t get those. Another thing would be to upgrade a DF neck to 3 sockets. On that note, maybe pick up some high slot bags. I’m sure there’s more, but that’s just off the top of my head.