You should definitely have both if you can. Creatine is one of the most widely studied substances and has been shown time and again to be safe, and has been used for years with no reported issues. Creatine is found naturally in many foods and the supplementation simply concentrates it a little more and gives lifters elevated amounts of it, which is not harmful. Most serious lifters take it because it truly is effective as part of a regular supplementation cycle.
Depending on the kind of creatine you get, be sure not to keep it in solution for long as it breaks down quickly. Stick with the powdered form. Some people have reported mild side-effects in the past such as slight bloating, muscle cramping (due to dehydration more than anything else), and gastrointestinal distress. Personally, I know many people who take it and not one of them indicated problems with it.
Whey is an excellent pre and post workout powder. It's best to go with the isolate form. Most whey supplements are comparable when coming from major reputable brands. I suggest staying with pure whey protein isolate and not going the weight gainer route. You can add maltodextrin or dextrin for your carbs separately if you wish.
Supplementation comprises only a small part of a routine. Good nutrition is the cornerstone of a successful lifter, something most people greatly underestimate the importance of. Most of your proteins should come from whole lean sources. This goes for the other macronutrients, too (carbs and fats).