Creatine won't build you muscle, creatine in laymen terms gives you more energy.

In a bit more details in increases energy stores by opening up pathways for glucose to enter the cells and be stored as glycogen in the muscles which means you will be able to work longer as there is more energy is on demand as this glycogen will be used as energy via ATP yadda yadda. However if you're not getting this energy in your diet creatine is USELESS.

Buy cheap. If you're going to get it get it cheap, it's all the same. Creatine monohydrate.

But I use it yeah. Only use it if you're dedicated to your weightlifting goals. You will noticed your muscles LOOK bigger a day or two after taking it, this is the energy stores

It's great if you go to the gym and go hard. Get it, but get it cheap. Take 4 week cycles of daily 5g. Then 1 week off whilst still working out. Don't take it if you don't work every muscle set - including legs. The fact you're a newbie makes me want to say don't get it yet but if you think you need it go for it. The first 6 months of bodybuilding is where you make the best gains so ideally protein powder for a newbie so you can actually make the gains. Rather than have the power to work out. It all goes hand in hand.