[Beginner issues] Serissa Variagata Bonsai - advice needed

Good evening all, just came across this forum hoping for some advice or help.

I recently purchased a new Serissa Variagata bonsai about a fortnight ago and have noticed 2 or 3 of the leaves are browning. It is kept indoors on a slightly sunny windowsill, I've been misting, watering and feeding when required. Here are some photos:

https://imgur.com/a/7VkyZel

https://imgur.com/a/sPjUi3G

Also unsure what to do with the "spindly shoots" at the base. These were in place when I bought the tree, any advice on these too would be fantastic.

Many thanks.

Serissa have a reputation as being temperamental about any change of their growing conditions up to dropping all of their leaves. If you are only seeing a few leaves brown in a fortnight you are doing quite well. Unless your house has very low humidity, I don't think I would mist. The spindly shoots at the base should be cut off since they will draw energy from the main tree. You can probably get them to root by sticking them in some moist potting soil and covering with with some clear plastic where they get bright, but not direct sunlight.

I am relaying what I have read on this forum over the past 30+ years regarding Serissa since i have never had one. Someone with actual experience may have more to say.

If you are relatively new to the agony of bonsai, some advice is offered.  Advise is like butts.  Everyone has got one and they usually stink.  
With that out of the way, I will proceed to give advice, which will probably not be taken.  Starting bonsai is like placing bamboo slivers under your nails.
You try and try, but still get hurt by the process.  WHEN YOU START BONSAI, choose a simple easy tree to work with.  Serissa is not that.  Yes, I have tried serissa. Variagata is the
clue word.  Any tree that is a variant will not perform well under the stress of bonsai technique.  Get a nice, simple Juniper or a pine from the nursery and work on that.
You will have less aggravation and less tears about the whole process.  Please!

Oldman had some good points about serissa and variegated plants in general. if you are limited to indoors then ficus are fairly easy to grow and develop. Just make sure you don't buy one with rocks glued on the surface of the soil. If you can also grow outdoors I suggest collecting some seedlings or getting small nursery stock of species that grow well in your area. I am particularly fond of maples and elms for beginners.