Step 1: Start out basic by buying the basic packs and bundles. Its best not to start out with the rarest cards you can find, because those are hard to obtain.
Step 2: Once you have started collecting basic cards, and have decided you like collecting enough to continue, buy more!
Step 3: When you feel your collection has grown enough, sell cards you have duplicates of, or just sell cards you dont want.
Step 4: Join online forums to help you scope out which cards others are selling, or to sell your own cards!
Step 5: Once you feel you have enough money, go and try to buy a rare card!
Tip 1: If you would like to buy new cards, Walmart and Target are your best options.
Tip 2: If you want to find the current value of cards, your best options would be TCG Player, Pokémon Prices, and Card Mavin.
Tip 3: Amazon is a great place to buy Vintage cards! Some good sellers on amazon are Troll and Toad, Core TCG, and Game Time TCG.
Tip 4: The best Vintage Products to buy are Single cards, PSA/Beckett graded cards, Sealed Booster Packs, and Sealed Booster Boxes.
Tip 5: If you are buying new cards, the best series to buy are The Original Pokémon Base Set, Jungle, Fossil, and Team Rocket sets.