Start with a DAW. Demo Live, Bitwig and FL Studio as those seem to be the most popular. Find the one that you’re most comfortable with, then buy a full blown version of that, depending on what extras you want with it.
Once you’ve got the DAW and all that comes with the DAW, you can look at additional software/plugins.
I’d say just focus on learning how to make sounds with just the DAW to start. If you have Ableton, you have everything you need. There are often lots of free sound packs available on the official site, as well.
If you are on a Mac, start with laying some sounds down in Garageband (FREE!) you can upgrade to Full blown Logic for a measly $200 if you feel comfortable with it and all your GB files will open no probs.
A midi keyboard or something like launchpad can certainly make life easier, But its not essential to have one starting out. Plenty of controllers come with Ableton Lite as well which can offer a cheaper upgrade path to Full Blown Ableton if you decide its the one you want to go with.
Definitely play around with GarageBand, theres pretty much zero learning curve between it and Logic when it comes to laying down a basic track, just “more of everything” in Logic.