I'm new to the world of bonsai and fear i've already ruined my first plant

It is a grafted banyan fig I bought from bunnings on the weekend, probably about 5 inches tall. I got bored just looking at it and decided to prune it. Unfortunately my blind trust in everything written on the internet lead me to follow the advice of the first website I looked at and cut off all the leaves. Checking more websites today most tell me to leave a few leaves. All I left was the small buds on the end of each branch.
Is it time to buy a replacement and start again or can i save this plant?
I soaked it in water after pruning and it is now in a shady area being watered whenever it dries out. Is this the way to treat a recently pruned plant or has the internet lied to me again?
Also it came in fake soil made out of some sort of plastic, surely this cant be as good as proper soil, should I re-plant it and if so when?
Any advice for this obvious rookie would be greatly appreciated