Hello Nick and welcome.
You have started on a most fascinating, enjoyable, rewarding and at times most frustrating journey.
Start simple and progress onto more involved engines thus gaining experience using your machines.
The time in the workshop will fly past, and on many occasions with very little to show at the end – welcome to model engineering!
My first steam engine was the ubiquitous oscillating type, followed by Rob Roy and Simplex with a few Stuart Turner and tools in between.
Take your time over your first few engines, so that you become familiar with your machines, as well as how different metals machine and behave.
You may in fact find you prefer to make tools only as many have.
DO NOT dispair when you make a mistake making/machining a part, and you will, it's part and parcel of the hobby in general and an affliction even the most experienced amongst us suffer from.
Seeing your first project come together is most rewarding and satisfying, as is the first time sat behind the loco that you built that actually pulls you and passenger/s around.
Geoff – Popcorn popper converted to coffee bean roasting ready to test.