To the OP
I too just recently started riding! I started in April but I can tell you I am having an absolute blast. Ill share some of my personal experiences to help you.
I started with a 2011 Honda CBR125R which is what I am presently riding. I am 6 foot on the dot and usually around 170 lbs. It fits me great and its so much fun on local drives around Mississauga. I started to get acquainted with riding within about 10-11 times being on the bike and although the 125 is great, I do wish I went with a 300-400.
The 125 with me on it can go up to and sustain 115 km/h. The acceleration is not as abysmal as people will make it out to be, but its no great. The problem non the less is that its not heavy enough to handle high winds on the highway. Essentially, I cant really take it on the highway with out being on high alert because the wind just feels like its in control. If I had a bigger bike, I would ride it to see my family in Hamilton, but for now, I can only ride the 125 anywhere other than a highway, I do ride it to work every time I can.
If you are sure that you will not be needing to go on highways this season AND your not heavier than 190-200 lbs. the 125 is a good choice imo for local roads. some 125's are bigger than others. for an instance, my 2011 cbr125r looks considerably bigger than a 2007 model which I had checked out prior to getting my 2011.
As for insurance, the lower the CC's likely means lower insurance. I am no expert in this field. I will say, I get a full tank of 92 octane fuel for my bike for $12. and its good for about 400 km's. Its really good for gas, compared to a car. So I like to take it to work when the weather is nice, and honestly, the money I am saving on fuel, offsets the insurance cost for me as a new rider.
I use fortnine which is a Canadian company out of Montreal. I dont know if their prices are the best compared to local shops but I have not been disappointed otherwise.
As for the schools, the training is so important imo and I went for the one closest to me with the nearest dates.
Perhaps, if I were to go back in time, I may consider having started on a Yamaha sport bike around 400 cc's. But at the same time, if this is going to be a life long endeavor for me, I appreciate that I will always know what a 125CC was like compared to all the bikes ill ride one day.
I am keeping the 125 for this season, but ill be looking for a 400 CC starting next April.
I have not yet dropped my bike. But I did make a lot of mistakes, all of which had absoloutely no consequences because I was riding a very forgiving 125! So start with a used bike, You will make mistakes, you will possibly damage it or wear out some parts while you learn, at least, you wont be doing that to a brand new bike for which you will likely be much more emotionally attached.