To start you need the heart of autohomy a Wemos D1 Mini NodeMcu.
Hopefully you have already one or another type of NodeMcu, there are many variants out there. If not, ask a friend if he can borrow you one until you can get one, e.g. via AliExpress directly from China. It takes weeks to get one from there, but they have free shipping and the costs are under $3 for one Wemos D1 Mini NodeMcu, so its my favorite way to order. If you have started ordering once you will find many other modules there, many of them costs only some Cents, including shipping, so you will order day by day new modules, while you are working with your existent ones and then from time to time small pakets with your new modules arrive and you can play with them. Sometimes I have 20 or more orders open, and it’s always a little kick, when one paket arrives and the special sensor module I want to play with next, is in it.
So while you are waiting for your first sensors that you have ordered, (a list of the parts I use with a direct link to AliExpress is here) you can start learning about NodeMcu and Programming in Lua. Then go further with Mqtt and NanoPi and read my blogs about my autohomy.