The game really wants you to pick the pret-a-porter Hunter character it offers you. That is the one that complements your companions. The game does not want you to make a character from zero. That option was added only because of the crowd whining, and still the designers warned that only people experienced with the pen and paper game might avoid screwing their PC right from the start. The Dark Eye is very unforgiving and there is not a human game master to guide you or soften the blows. If you make a design mistake in your character from the beginning, it will be difficult that you can solve it later.

By the way, Hunter is a very flexible and interesting class in The Dark Eye. It is the profession/class of the protagonist in Chains of Satinav, by the way. And his lance plays along beautifully from the second row with first-line fighters of less than average height...

That said, once you have your Hunter PC, it will be up to you to apply experience gains to your party. There are guides online for that aplenty. There are many options. Some swear by the traps, but others do not use them, for example.

All in all, it is a tough but rewarding game. Money is indeed scarce. It helps if you put yourself in the situation of your party: you are runaways making your way through the sewers of society. Consumables for camping will be more useful than spending all your cash on a nice weapon. Bear with the poor arms you get at first. You will have the chance to get better ones as rewards. Try to use your money to get consumables and to complement the gear you get from rewards with the pieces that you might be lacking (but still do not rush to buy: be patient) and keep a safety reserve just in case.

Also, try to do the easy missions first, and do not even consider dealing with the dwarven brothers before getting Neera in your team. Without her, it will be way more difficult.