So, if the S2S available to you is okay, you should get a jointer first.

I thought the purpose of s2s was that one face was already jointed
flat, with one edge jointed at 90 degrees, so that you only need a
planer for the opposite face and a table saw to rip the opposite edge.
IOW, you need the planer first and not the jointer.

To the OP, I would avoid both the planer and jointer until I could
afford both. You can always buy s4s and use plywood. You could start
on some shop projects with the plywood to help get set up and get some
practice. You can also make some smaller stuff like boxes or magazine
racks that avoid large glue-ups. Once you get the money together, I'd
get a lunchbox planer and something like the grizzly G1182HW at the
same time, then go out and buy some rough-sawn lumber.

brian