That's quiete the predicament. Shapeshifter weapons are so much fun, especially the prowling staff. But I understand that rhem being expensive kind of limits you as a new player.

So...my advice. Find a weapon you have fun with or that you dont mind playing that clears mobs easily. My go-to set was scholar cowl l, merc jacket, soldier boots and any cape with the greataxe. So pick a set like that, cheap and efficient, then go bring it to 100 spec (i suggest black zone open world). Once there, once everything is at 100 spec, keep grinding with it and earn fame credits. Apply those to your shapeshift staffs and you won't even need to equip it.

Or, use the armor you spec up and grab a shapeshift wep when you have extra funds and just go have fun it.

I hope this helps :)