I live in philadelphia, pennsylvania, where the weather ranges from 100 F in
the summer to 20 degrees and colder in the winter.
Should i just repot it to make it easier? should I get some kind of light
for the plant?

The first thing you need to do is find out what kind of a tree you have. This
is vital. Does it have little needles, like a spruce or pine tree, only tinier?
It probably does, in which case it is a juniper, and will die if you keep it
indoors too long. Since it is not accustomed to winter right now, you must keep
it in a cold place just above freezing. If you don't have an unheated spare
room or a sunporch, wrap it in plastic and put it in your refrigerator. It
needs to stay cool until next spring; then put it outdoors for the summer.
The term kengai does not tell what kind of a tree you have. It is the style,
which means cascade. The end of the tree hangs down below the pot, as though it
were growing on a cliff.
Do not repot the tree now. You can repot it in March, but not until you read up
on the subject & know what you are doing. Meanwhile, if you have those glued-on
stones, pry them off at once.
Fluorescent lights are excellent for tropical bonsai, like Ficus or Serissa,
but wait until you know more about the subject.
Iris,
Central NY, Zone 5a, Sunset Zone 40
"If we see light at the end of the tunnel, It's the light of the oncoming
train."
Robert Lowell (1917-1977)