just a heads up that game is based on team play and the holy trinty (tank/dps/healer)
goblins only have dps/healer... Ranged Squig, Melee Squig, Dps Shaman, and Heal Shammy (although shammy pretty similar)
so you wont have guard to mitgate incoming burst damage...
you also wont have bork and choppa CDR (cooldown reduces) which really help MSH and Shammies synergise
not so long ago morale bombing got nerfed (last year) ... this use to be a big thing and 4 Squig 2 shammies could wipe alot with it crazy morale drop burst but no longer
doing dungeons will need to take tanks from pug or your allies if you care about doing pve content (gunbad/bb/be/bastion etc)
That being said... goblins are the kings of kiting with access to racial tactic for +movement ... but also have uncleasnable snares (puddles from shamans) and m2 from Squiggy's... alot of heal debuffs and burst damage
RSH is good ST, lacks AOE besides it morale dmg...
MSH is good aoe (if CDR from orks) but without a guard likely to blow up on front lines
Also Shamans are king in t1 combat lvl 1-15 with their dots and self heals
Farm t2-t3 secenarios and try maximise your renown pre level 40, (there is xp scrolls from quartermasters in warcamps to try reduce you level too fast) renown events, usually on weekend battlefront sc's etc... I think you will get the most fun in the short term in t1 orvr, t2/3 sc's ... t2-3-4 orvr is binded, t4 sc's... you will come across higher level, better geared and balanced premades so will be rough when you start off in t4 for a little while.
in end game depending how big you going to make your guild or if you are part of alliance wb... no tanks will be a bit rough, as fights will be a bit stationary around objectives, but if you kite and rotate well group of shamans instant rezzing, puddling, fodg and the heal debuff and st pressure ranged gobos can put out will be annoying to some degree against unorganised and weak enemies.
gl with your project, i raised some of the concerns and potential issues and strengths you might come across eventually
Also kill bitterstone thunderers they are a dwarf guild and will snipe you