I agree with Jim K on most of what he said.
I do not carry a patch kit for daily rides but I do carry a spare tube or sometimes two. And a couple tire levers.
I always carry a pump. I like pumps similar to the kind Jim K suggested, one I like is a Road Morph G, the other is the Lezyne Micro Floor Drive. Both of the ones I mentioned also are like miniature floor pumps.
On average I get about one flat a year. The patch kits that use a small tube of glue work much better than the ones that have self adhesive already applied to the patch. Watch two or three or four youtube videos on how to patch a tube before trying it yourself.
Before you buy a tube, make sure you get the right kind of valve on it, they come with either Shrader valve (like a car tire valve) or a Presta valve (smaller diameter with a small knurled knob on the stem that you unthread first before inflating tire). You probably should get the same type of valve that is on the tires on your bike.
There are a variety of ways to carry this stuff, a small tube and a few other items can go in a small bag under your saddle, they make bags for that purpose. Pump usually goes on a bracket on the bike. On most of my bikes I have a small plastic bottle that holds this stuff, that bottle fits nicely into my water bottle cage under the downtube. If I recall the Raven can be fitted with a water bottle cage under the downtube.
The reason I am not suggesting any other tools right now is I have no clue if you have much mechanical aptitude or not. If you do not know how to use them, I am not sure what value they offer if you carry them.
A youtube video would not tell you how to remove a rear wheel that is fitted with a Rohloff, that needs some specific instruction. I do not have a Raven, my Rohloff is the other kind so I will not elaborate here.
Something that you should learn fairly soon is how to adjust chain tension and also how to recognize when you need to do it.
If you have a leather saddle, you should have a waterproof cover that goes over it too.