Hello, bonsai lovers

I've been wanting a bonsai for a long time, finally got not one, but two. Mallsais from Home depot. (gift)

It came with pebbles glued to the top, so can't feel the soil.

My two most pressing questions:

1. Do I repot (since the pot is shallow, as expected from retail) even though it's not the season? I read that in the case of mallsais, this is needed, but everything else seems to point to don't repot unless it's the right time.
2. What is the best soil? I did a lot of reading on this, and got overwhelmed.

I really really want to keep them alive and so I am in a kind of a "panic mode". Is removing the pebbles and making sure they're outside and watered properly enough to keep them surviving until the right time to repot?

Thanks in advance.