Oppo, teach me about...loans?

In preparation for the 944 purchase, I've been learning more about loans, but there are still things I don't understand, so I'm asking for some help.

Now with the 944, I have to take out a $3000 loan for it. That's not a problem because I can easily afford it. The problem is that I grew up not knowing that having established credit is needed to actually get a loan.(-_-)

Now the solution to that is obviously getting someone to co-sign; enter my dad who seems to be for me getting the car, which is good! Here I am thinking this is gonna be simple and all will be fine. But remember how I mentioned my mom wanted to get a Volvo XC60 T6(aka $45k car)? He then comes back to tell me he needs to check his credit score first; to which, I think to myself, "no big deal, go check that score and all will be fine!". And then he says he's not sure if he can take out two loans for two cars because my mother no credit??(I think he means not good credit). And I'm like, "Wait. WHAT??". So here I am, confused as to how this is possible, as I was not aware that you're credit score and income and other such things limited you to how many loans you could take out a year of something? Is this true?

I was/am thinking of possible solutions, and one of them was to try to put a big enough down-payment on the the $3k loan, say about $400, that way, I assumed it wouldn't be that big of a deal and maybe easier to get the loan? Or maybe I could ask another local relative to co-sign? I'm a bit lost, so please help me out Oppo? :(

EDIT: I Had a thought, wouldn't co-signing and paying of the loan be a start to establishing credit for myself?? That would be great right, as we've all got to start somewhere!