To make a new deck, first notice that all of the cards other than the Trainers have different Energy types on them. Your deck should probably include one or two of the basic Energy types, and you can choose to add some Colorless Pokémon if you like. If you just choose one Energy type, you will always have the right kind of Energy for your Pokémon but not as much variety. If you have several Energy types, you will have more Pokémon to choose from, but you will run the risk of sometimes not drawing the right type of Energy for your Pokémon. And be sure your deck has enough Energy cards (most decks need 20 to 25).
Once you choose your Energy types, pick Pokémon and Trainer cards that work well together. Do you want to build up big Pokémon to crush your opponent? Then put in a lot of Evolution cards and some Trainer cards, like Poké Ball, that help you find those Evolution cards.
It is a game rule that you must have at least 1 Basic Pokémon in your deck. A "Basic Pokémon" is considered a Pokémon with "Basic" as the Pokémon’s Evolution Stage.
After you make your deck, play it as often as you can against as many other decks as you can. See what works and what does not, and then make changes. If you keep working at it, you will have a deck that will show everyone you are the greatest Pokémon Master of all time!