Dave Smith and Gareth Slee write:
The train station is quite close to your hotel, but unless your
destination is on the main corridors you are probably better off
taking the bus. Canadian rail service is infrequent and usually
runs late. Bus service is much more frequent and tends to run on time.

Well I'm looking to travel to Niagara and then onto Cleveland OH.
I'm hoping the buses won't be fully booked for my dates (10th Feb and
12th Feb) .

There are only 2 or 3 trains each day from Toronto to Niagara Falls.

One on the morning (an Amtrak train that goes on to New York City,
but operated by VIA Rail Canada crews in Canada), one in the evening
(a VIA train that terminates at Niagara Falls, Ontario).

Buses run almost hourly.

It wouldn't occur to me to buy a ticket in advance for a bus to
Niagara Falls. I would not expect the trains to be full either at
this time of year, although I could be wrong about the morning train.
I would not expect these trains to run significantly late on this
particular journey[1], so unless the fare is a factor, the choice
is mostly a matter of whether you prefer more comfort or more
flexibility as to time.

[1] The onward service to New York -- and the same the other way,
forming the evening train from Niagara Falls to Toronto -- is
subject to significant delays at the border and over the course
of its trip. This also means that if you wanted to go from
Toronto to Niagara Falls, New York, you would be better not to
do it by staying on the train.

The Niagara Falls train and bus stations are across the street from
each other, in the old downtown business area, which is pretty seedy.
It is about 2 miles down river from the falls.

More like 1.5 miles. By the way, downriver is north -- if you cross
the river from Canada into the US, you're going east. The bridge near
the train and bus stations is no longer available to the general
public, but if you want you can walk across via the Rainbow Bridge,
near the falls.
--
Mark Brader | The only trouble was, no despot had the resources to plan
| every detail in his society's behavior. Not even planet-
Toronto | wrecker bombs had as dire a reputation for eliminating
| civilizations. --Vernor Vinge, "A Deepness in the Sky"

My text in this article is in the public domain.