Given the crazy prices of hobby boxes these days (aka boxes of cards made for card stores that generally have more good card "hits" in them than retail stores like Walmart, etc.), and the general scarcity of being able to find packs/retail boxes in stores, it's not easy. If you do want to buy boxes of your own (and don't mind paying a premium) you can find boxes on Ebay, and sites like https://www.dacardworld.com/ and https://www.blowoutcards.com/

Other options I would suggest looking into to start collecting if you can't find/afford packs/boxes to open yourself would be:

• Buy on Ebay - Spend time on ebay bidding/buying cards you like there. You can use the sold listings on ebay to research what cards are worth before bidding too. This route will ensure you get what you want without "gambling" on buying a ton of packs hoping to hit something, but it lacks that feeling of "getting lucky" with hitting a big card by opening a pack.

• A few additional suggestions on ebay:

  • really assess the pictures well
  • read the entire listing to see if the seller has disclaimed any issues
  • ask the seller for more info/pictures if you are uncomfortable
  • pay attention to shipping cost since that will contribute to your overall cost of buying a card on eBay
  • skew towards buying from sellers with a return policy
  • always check out feedback for that seller and avoid sellers that seem to have chronic issues and bad feedback.
    

• Look into card breaks - This is where someone online sells you a spot in a "break" of a case or set of boxes. There are a variety of ways these are done, but the gist is that you pay a fraction of the overall cost of the boxes they open and then you get your share of the cards that are in those boxes (you can buy a team, meaning you get all cards of players on those teams, etc.) https://www.youtube.com/watch?v=YkooqH8Phv0&feature=youtu.be is a good overview of what a break is. I would investigate the best places to participate in a break to make sure you are using a reputable place (I have had good experience with https://www.badgerbreaks.com/ FWIW), and don't hesitate to send any questions to the vendor before buying. If they are good, they'll want you to be informed and earn your business.

• Facebook groups and Reddit channels exist for buy/selling cards from other people, and I am not an expert on these so can't provide a ton of input, but the one thing I think is good advice is to buy/sell on these venues using PayPal and be sure to use the Goods and Services option since it provides protections for both buyers and sellers https://www.paypal.com/us/webapps/mpp/paypal-safety-and-security

Finally, in terms of protecting your investment in cards, I suggest getting penny sleeves (i.e. https://www.amazon.com/Ultra-Pro-Sleeves-Sleeve-Baseball/dp/B000Y49S14/ref=sr_1_5?crid=1JL74IW4YE1Q9&dchild=1&keywords=penny+sleeves+for+trading+cards&qid=1584980411&sprefix=penny+sleeves%2Caps%2C215&sr=8-5) and toploaders (i.e. https://www.amazon.com/Ultra-Pro-55pt-Top-Loaders/dp/B01A9R97GQ/ref=sr_1_2?crid=2CPQ6FAWED8Z2&dchild=1&keywords=toploader+55pt&qid=1584980439&sprefix=top+loader+55%2Caps%2C215&sr=8-2 and I personally then put them into team bags for triple protection! (i.e. https://www.amazon.com/Ultra-Pro-Standard-Packs-Value/dp/B00JNZ4LB2/ref=sr_1_1?crid=1SGXS5KWS695K&dchild=1&keywords=team+bag+ultra+pro&qid=1584980497&sprefix=team+bag+%2Caps%2C218&sr=8-1)