Advantages of living in London
1) Public transport easily accessible almost everywhere.
2) Walking is good exercise. Pedestrian-friendly
3) More courses available
4) Public libraries and coffee shops available almost everywhere, useful for studying without being disturbed
5) Safer than other cities, that doesn't mean you should let your guard down completely
7) Halal food options
1) Some areas have high crime rates, especially in isolated areas and areas where tourists visit like the London eye, pickpoketing can happen.
2) Tahara and najasa problems, especially in public bathrooms.
3) Weather, it can sometimes get too cold, especially in the winter.
London is a good place to live. However, safety and security, and climate changes can be a problem. My advice is to take care of your belongings especially in large crowds, don't take the shortcut to your house at night by yourself, it may seem like a good idea in order to save time but your safety is the most top priority. Instead walk through well-lit areas at night. Trust your instincts. If someone ever makes you feel uncomfortable, then walk away and report them. It is better to be safe than sorry. Keep your doors locked whenever you leave the house, even when you are in it.
That doesn't mean you should spend the rest of your life paranoid. Have fun, but be cautious. For the weather conditions, try to be prepared. Read the weather forecast and wear a coat.