In Spain in almost all short distance trains “cercanias” you just carry your bike with you; that’s all. The medium range trains called “regionales” have a special department for bikes in the end of the train.
There are exceptions, but so far, I have found no way to know them in advance
Long distance is more complicated. Typically you can only carry bikes in your overnight department where the only available space is the bed; is up to you your own accommodation.
I travel very often in Andalusia. There is a fairly good and cheap bus network that takes your bike all right: when boarding the bus, just put it in the luggage department without asking, otherwise they will charge you something for it.