Here is the answer to the most trending question.
But first, a usual disclaimer that you don't need to take any supplements. Supplements by their nature are an add on to proper nutrition, sleep, and training practices.
So if you're trying to build muscle, I'd first focus on balancing out your macros, tracking your food, and getting the right amount of calories from clean, whole foods.
TDEE Calculator: Learn Your Total Daily Energy Expenditure is an excellent way to get started on that front.
Now to supplements.
Whey Protein Isolate
Protein powder has been a staple of gym culture for decades. Whey Protein especially is a favorite because it works. Protein powder is a convenient way to hit your protein goals each day. I get about 200g of protein per day. If I were to get that much protein from the chicken breast, that'd be eating about 2lbs of chicken breast per day. That's not very fun.
Protein powder helps you conveniently hit those numbers. So you're not spending all day chewing steak or chicken breast. Protein powder should not be your primary source of protein, though. You need to prioritize lean whole foods. I don't eat red meat very often, so most of my protein comes from chicken breast or thighs, lean ground turkey, fish (tilapia, catfish, salmon, shrimp), and eggs.
I say whey protein isolate because whey protein comes in two different forms. Isolate is slightly more expensive, but it's purer and less likely to have lactose in it that can cause digestive problems at high volumes. Most protein powder will be a concentrate. Or a blend of isolate and focus, make sure protein isolate is the first ingredient. Gold Standard Whey from Optimum Nutrition is found in most grocery stores and is a good option that isn't stupidly expensive, so do that. (The vanilla ice cream flavor is way better than the Dutch chocolate).
If you don't want to deal with whey protein for whatever reason and wish to plant-based. I'd recommend looking for a plant-based protein powder that uses pea protein. Plant-based protein generally tastes the best. Rice and hemp protein taste like sand and a potted plant, respectively. Soya protein is stupid expensive. Plant Fusion and Vega Protein make good protein powders for the plant-based athletes. I used Plant Fusion for years with a lot of success.
Creatine is not a steroid or anything like that. Creatine aids in muscle force production basically by helping pull water into the muscles and helping replenish a chemical in your muscle that allows the muscle to use energy during activity (that's the super simple version). It'll help you be a little stronger and maintain stamina in the gym, which will aid in muscle growth because you'll be able to have more volume in the gym.
In general, it helps your performance. Primarily for shorter-term movements. It's less useful for long-duration exercise like long-distance running. You will notice some water retention when you start using it, it's okay, keep training, and you'll stop seeing it.
I like to buy Creatine as the little caplets you can get like 250 servings for like $20, which is a good deal. I get the ones from Optimum Nutrition as well (not sponsored).
One of the most popular substances in the world, the benefits of caffeine, are numerous. I like to buy caffeine pills. For $10, you get 100 caffeine pills are 200mg. Which is a cup and a half of coffee or a monster or something? If you think about how much money it's a cost to buy 100 energy drinks, it's a cost-efficient way to get your caffeine in.
I typically don't take pre-workouts because of all the junk that's in them. A single caffeine pills and some Creatine does the trick.