I'll give you a few pointers to getting some nice GP gains.
They are all skiller friendly as I am a 3cb skiller.
This methods are not the most efficient just something that will get you started.

Method 1: Go towards a high goal of Fletching preferably 99 to get yourself a nice cape.
Fletching profits a great beginners stack while working toward a 99.
Depending on the market Fletching can profit from 6-10M during your trip to 99.
Your goal should be getting to 70 Fletching for Yew Longbows and only string them because they earn more gp/hr.
When you reach 85 check the market to see if Magic Longbows profit.

Method 2: Cooking is another great beginner skill to make some decent profit while achieving a high leveled stat.
Cooking can range from a 4-6M profit to 99.
I myself only cooked Monkfish to 99 because of the Shark burn rate.
If you can get yourself a pair of Cooking Gauntlets cooking Shark is better.

Method 3: Farming ... Farming is by far the most efficient money making method when it comes down to effort/gp.
10 minutes of work can profit you 100k p/hr.
Farming herbs profits greatly and requires no effort, just set your seeds and await your fortune.

TL;DR: Using cooking, fletching & farming herbs to get some starter cash.

Hopefully you give one of these a shot, great times ahead.
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