Hi Vincent
As you are a new rider I assume you will be going for a small capacity bike ?
There are plenty of small capacity bikes that would be suitable.
Japanese would probably be favorite as they tend to be well built, reliable and parts are a reasonable price and easy to source.
Have a look at some of the posts in the build section of the forum, plenty of ideas there.
It's possible to give almost any bike a cafe racer look but some work out better than others !
Choose a bike, get yourself a 'Haynes' manual and get the spanners out !! It's not as hard as you think, just take your time and follow the manual for dis-assembly and putting it back together.
It's also a good idea to take loads of photos as you progress - can be helpful later to remind you how it should go together.
Also when you strip off any parts, bag them up and label them - especially nuts and bolts and fixings - there are lots of different sizes etc and it's a nightmare if you just throw them loose in a box !!
I use see through plastic 'freezer bags' that have a panel that you can write on in biro, really helpful down the line.
Good luck
Cheers
Mike