I need help!

That question has a complicated answer, as different types of game require different approaches. Though I'm still learning to program myself, so I can't offer much advice on the topic, I can suggest that you do some poking around online, searching for tutorials on how to make the kind of game you're trying to make. There are a lot of incredibly helpful resources out there. The biggest issue you'll run into is advice for specific languages, most of which will be gobbledygook to a beginning programmer. Therefore, try to find a generic tutorial, something with some guidelines to follow. Then, learn the code you need to implement those feature. For example, I'm currently working on a roguelike and I'm following a 15 step guide I found on RogueBasin. You'll be able to get much more help from these forums once you run into a specific problem, and so far I've found people here are nice and quick to offer help once you know what sort of advice or problem you've run into.

It's not that hard just start messing around with it. Follow the guides here > http://smilebasic.com/en/e-manual/24.php and follow the ones on the manual on the 3DS as well.

If you already know print and input then you're almost there! Now you just need to know IF...THEN, GOTO, and RND. With those five commands you can make a simple game where you have to guess which number the computer is thinking of:

NUMBER = RND(100)
TRIES = 0
PRINT "I'M THINKING OF A NUMBER BETWEEN 1 AND 100, CAN YOU GUESS WHAT IT IS?"
@START
INPUT "ENTER YOUR GUESS", GUESS
TRIES = TRIES + 1
IF GUESS = NUMBER THEN GOTO WIN
IF GUESS < NUMBER THEN PRINT "IT'S HIGHER THAN THAT"
IF GUESS > NUMBER THEN PRINT "IT'S LOWER THAN THAT"
GOTO START
@WIN
PRINT "WELL DONE! YOU GUESSED IT IN"
PRINT TRIES
PRINT "TRIES"

Start off with simple games like this to help yourself learn the language. And try out the functions listed in the manual to see what they do. They all have example usage which you can usually type verbatim into Direct mode to see what they do for yourself. (It's one thing to read about the SPSET or GTRI functions, for example, but seeing the results of them for yourself will help you understand them) Good luck!