Let's see what a wallet starts!

[Tugadude]

Welcome to the wacky world of leather!  Crafting, I mean  As far as your branding, there are folks that advertise here that can make up custom stamps for you.  Stamps that you can heat up or just hammer, whatever floats your boat or meets your budget.

Those wallets you referenced are super easy to do and a great way to dive into leatherworking.  I would just take a piece of paper and cut it, fold it, and get it to the size you want and then use that as a pattern.  Try to add your own "touch" to it so you aren't doing a direct copy.  That could be different angles, rounded corners, different-shaped thumb grooves, etc.  You can google minimalist leather wallet and look at hundreds of examples within seconds.  It will give you ideas you can incorporate into your work.  I find it very simple to look at examples and make a template, but some folks can't do that.  We're not all wired the same.  For help on that there is a sub-forum here on templates and some very nice people there can help.

Good luck!