Welcome to the forum. So you bought the tank an added your fish right away? Just wanted to make sure I'm not mistaken by your post. If so you know your now doing a "fish in cycle" right?
It can be done and nothing to stress over.
"When creating an aqua scape, strive for the beauty of imperfection, as its art and there is no wrong or right, it's left open for interpretation" James Findley