I'm not quite sure how all this works but you all seem to know what you're talking about and have been very helpful to other people so I'm hoping for the same help!
We will do what we can
I've got a "Ficus Microcarpa" indoor bonsai tree that came from Homebase, it's displayed in a black ceramic pot with white stones round the top of it... although this looks good I'm worried it's not practical? the pot has no holes at the bottom of it so I don't know how to water it properly.
Ok, Good call
It needs to have the rocks removed [I am presuming they are glued down, Yes?].
A pot w/ a drainage hole is a requirement [It need not be fancy-That is up to you-Plastic is fine also, You will probably find that it needs new soil also.
Please read these stickys for additional info:
This guy literally wrote the book on ficus:https://www.bonsaihunk.us/ficusforum/FicusForum.html
Another care sheet for you here: https://www.bonsai4me.com/SpeciesGuide/Ficus.html
And see the links on this page for further care:
[Especially the ones on: Beginners, Soil, Watering and Indoor culture, The others will be helpful also but start with those.]
You have some reading to do
Pictures are always helpful, [url=https://www.helpfulgardener.com/forum/viewtopic.php?t=3557]Here[/url]are some photo tips for more effective pictures.
And finally [url=https://www.helpfulgardener.com/forum/viewtopic.php?t=3343]Here[/url]are some inspiring bonsai photos if you need a break from all that reading...
I hope you find these helpful, Let us know