I heard I need a DI Box when recording things properly??
That's for one instrument only right? How do I record a band, playing all at once?
Do I just need a decent recording mic? Or do I use a DI Box for each instrument, plugged into the same thing?

How do I even use a DI Box?! Please help!!!!
The number of instruments you can record will depend on which interface you buy and how many inputs it has.

What are your aims for recording?

If you're hoping to create a demo CD for your band, you would be better off renting a studio for a day or two and having them create it for you. Recording is an art which takes a long time to learn, anything you create on your own will not be up to standard until you have spent a long time learning and practising.
Gibson LP Traditional, LP GT, LP Studio, SG Standard x2
Barber Tone Press > EHX Worm >TC Polytune > MXR Custom Badass 78 > EXH Glove > EHX East River Drive > Zoom G3 > TC Spark Mini Booster
Laney VC30
Marshall TSL602
Jet City JCA22H
My SoundCloud
You don't need a DI box, you need an interface.

Should you choose to buy a DI box at a later date, is up to you, but having owned nearly all of them under ~$200, there's not much point in investing in one, when your interface's built in Instrument "DI" Inputs, are likely just as good.
Quote by Dave_Mc
I've had tube amps for a while now, but never actually had any go down on me
Quote by jj1565
maybe you're not saying the right things? an amp likes to know you care.