Recently I was asked by someone who was just starting to learn to read Tarot if they were too inexperienced to read for themselves. I didn't think so. That's the best way to learn - reading for others when you haven't built up your skills base yet is a recipe for disaster if they take your reading with the same seriousness as a reading from a more experienced person who isn't just feeling their way into it.
But be a bit careful - don't read on the same subject too often, especially if you've already had a reading from someone else on it. Do the work that issue requires in your life first, before you do more readings. A reading simply shows you the next step to take in any area of your life, the things you need to do or stop doing. Until you've done that, another reading will be pointless and perhaps harmful (your even asking the question implies that the difference in cards pulled has already harmed your confidence in your cards and your ability to read them).
After all, what happens when you keep pestering people about something? They get annoyed and less responsive. I believe so do Tarot decks, too, with over-use on the one subject. Think of other things to read about, even if it's the old standard: "what do you want to tell me now?"
In the particular instance where the person has recounted first drawing the Ten Cups iin a reading, then later drawn the Ten Swords and was puzzled by the difference, I'd pull back a bit, and ask what meaning the number ten might have for you personally. Have you lived in a house numbered 10? Do you work on a team of ten people? Is it numerologically "your" number? Is it a significant number or a number surrounding someone you know?
While you're still learning and unsure, why not pull a card every morning? Look at it, think about it, write it down. Then at bedtime that night, look at it again, and see if it relates to anything (or anyone) in your day that day. This will help you get familiar with how you personally read the cards (everyone is different).
You might also want to play Tarot Solitaire as well. It is played like windows solitaire, but with Tarot cards. Lay out an extra two columns, instead of alternating "reds" and "blacks" keep each suit to itself, and run the Majors starting only with Card Zero and Card Eleven (the way the suits start with Kings), in strict numerical order.
This game takes time. Like regular solitaire, it will sometimes work out and sometimes not. It's interesting to speculate on which suits you can't get to work out, and how they are currently important in your life. But mostly, it keeps in the images of your deck in front of your eyes, and you learn by absorbtion and familiarity.
Good luck, and enjoy your Tarot deck.