Be safe, be seen!!!
We all know that safety is everything, and that is no truer when it comes to cycling. Every day, cyclists on the road are injured or even killed because they were not seen. This often is related to a driver's lack of concentration at a junction, or even the cyclist is at fault as they're either over-confident or not used to riding on the roads.
The best way to prevent road accidents is to be seen. This could be wearing high-visibility coloured apparel, dressing up your bike in flashing lights, or having reflective clothing. There are many things you can do, but the best way in my opinion is reflective gear, this can be something like a builder's high-vis jacket, a purpose made shoulder strap/belt (I don't know the actual name, I just have one, well, two!!!), or applying iron-on reflective tape to regular clothing.
Another way is to set up your bike with reflectors of some sort. This can be the usual white & reds you would have on the front and rear, you could apply reflective decals or tape onto your bike, or you could go the whole hog and cover your bike in retroreflective vinyl (see HERE!!!), but however you do it, make sure it is street legal (for example, the police may have an aversion to you using blue and white in certain countries!!!) and isn't too distracting to drivers, you wouldn't want to cause an accident by trying too hard to avoid being in an accident!!!
And of course, lighting for night time riding is absolutely essential, all you need is a red light on the back (flashing is a bad idea as it could trigger an Epileptic seizure in some drivers, so best to use a fixed light), and a white light up front. These can be battery or dynamo powered, so long as they are lit while you're moving. LED lights are best for size and battery use, the cheap Pound Shop type lights tend to be big and bulky, and being incandescent "Krypton" bulbs, they tend to run the batteries down pretty quickly in comparison to a 9x LED light.
So, to sum it up, have a look about for ideas to stay safe, visit cycle specialists for advice on what to buy, and of course, enjoy riding your bike on the roads!!!