If you've been eating enough fibre and drinking enough water then your faeces (poos) will probably be yellowy-brown in colour, they will float a bit in the toilet (they won't sink to the bottom)...and they won't be sloppy, either.
I wouldn't worry about looking all the time but every now and then it doesn't hurt to check.
If your poos are not usually like that, or if it hurts when you go to the toilet, then it might be worth while having more fresh fruit and vegetables in your diet.
And if you are worried about it--talk about it with your parents or a doctor. Even if you feel embarrassed, it's always worth checking up on these ordinary but important things.