If you do not have a lot of plat/items, the most important thing to twink on a lowbie Shaman is a good weapon. Shamans are very good at melee from levels 1-40ish. This will save you more time on leveling than anything else if you solo for a decent amount of your playtime.
https://wiki.project1999.com/Special...Blunt/AllItems This is a useful page to find good weapons for a Shaman, order it by damage ratio.
While you say you will probably not leave Kunark until your 30s, it may be a good idea to make a trip to east commonlands at some point to buy a decent weapon. There just aren't a lot of Shaman weapons you can get in Kunark at a low level that are any good. Most good Shaman weapons drop from higher dungeons, like Poison Wind Censor, or are found on a different continent, like
https://wiki.project1999.com/Gatorsmash_Maul . There are a number of good and cheap options on the 2h_blunt page I linked for only a few hundred platinum, which is not difficult to get even at low levels.