Hello, I want to know if it is possible to make purchases by steam and without putting a credit card, only for bank slip.

Second question: is it possible to buy booster and tori prime by steam account?

First question is matter of what payments Steam accept. First of all note that "card" payments don't necessarily mean you need credit card, if you have a "normal" bank card card you use to get money from ATMs, it should work. But let's assume you don't have card at all, you need to take a look at accepted forms of payments.
I think the closest way to what you want would be that sofort/directEbanking. I haven't used it though, so you'd need to read up.
There's also paysafecard, you pretty much find a local shop that sells them (they should be available all over the world, really), buy the card and get a code, provide it while paying.
There are some other ways of paying but I'm not sure if they're what you need and haven't used them neither.

Regarding booster/toriprime via steam:
They're currently available via paypal only. I'm fairly certain boosters will be available via steam in the future, but right now you must have paypal (which requires bank card).