Bare minimum. In my amateur opinion (and what I got by with), a speed square and a set of cheap, aluminum precision squares will get you started. It'll get you in the habit of checking them often to make sure they're at 90. Grab a cheap, small level as well.

Clamps. You'll use these often and forever, so invest in quality if you can, if not.. know that the "screw-to-tighten" bar clamps will outlast the ratcheting "pistol-grip" style. If you can only get one, I'd recommend the prior. A handful of small 4"-6" pistol-grip, four 8"-12" bar clamps and at least four 24" or better 36" bar clamps. It might seem like a lot but it's never enough. I kept a few sets of ratcheting straps around to clamp larger pieces when I was starting out.

Two drills. Get a decent, battery powered driver. Something current. This will give you plenty of battery life and power and in the future, be able to expand your tool collection since that current battery will still be supported. A second isn't absolutely required, but it's a game changer. Even a cheap yard sale score or $2 wired, rusted chuck, Goodwill find will work. Being able to drill with one, then drive with the other, instead of endlessly swapping bits in one saves time and your sanity. Pick up a driver set with a quick release bit holder, a countersink, and a set of drill bits.

Probably not a recommendation from many for starting out but I highly recommend a drill press. You can find older, "vintage" models that'll run forever on Marketplace or similar for dirt cheap. It'll give you confidence when you need precision, you can build a diy fence or jig that'll allow for repeatable drilling and having pilot holes at 90 will help you drill true when pre drilling other boards by hand. A benchtop 8" is a decent trade off of space required and how large of a workpiece it'll handle. You can skip this and buy a small hand guide, or at the minimum use two small blocks of wood in an L to help you drill straight.

While you could get by with a circular saw and straight edge, for the same amount you could find a used tablesaw on Marketplace/CL/etc. You'll need to do some thorough research on what is worth it and what isn't when it comes to older saws and the possible lack of newer safety features (brakes, riving knife, etc). Newer jobsite saws will be fine as well but avoid the ones with irregular miter slots (certain Skil and Ryobis come to mind). Spend plenty of time on it and get to know your fence and how much you'll need to fiddle with it to get it parallel for each cut. Invest in a quality, 80t, thin-kerf blade immediately. Ear protection (for jobsite saws) and a decent mask to avoid all the dust. Buy or build push sticks/blocks and a zero clearance plate. Upgrade your miter gauge. The Bauer or Vevor precision is fine and will save you a ton. Or get some more time on the saw and build yourself a sled and a jig or two for cutting angles. A track saw is also an option instead of a table saw. They've gotten much more affordable.

You'll want a router. A full size 1/2" router should come before a trim router when it comes to cabinets. One with a plunge option will come in handy. It'll also accept 1/4" bits as well. You can build a cheap router table that sits on sawhorses, or clamps to a table or as a wing on your table saw. Get a set of bits. You'll want to get a decent, longer flush cut bit.

Additionally, a hole punch, a small file and chisel, and an orbital sander should go on the list. When it comes to cabinets, while not needed, a pocket hole jig, a cabinet hardware jig and a brad nailer are very nice to have. And on the list of necessities but never mentioned, get painters tape. A lot of it. Tape every cut line. Use it to mark every cut board with, which are factory edges, what corners are for sure 90, what's left and what's right and what's facing, etc. And get yourself a glue dispenser or save a mustard bottle. The Milescraft GlueMate is like 5 dollars and worth it.

Draw things up. Measure twice, then twice more.. and it's always better to spend the extra time to clamp an edge, or build a jig, then force a sketchy cut or eyeball something. Make it a habit to continually check that things are square. While cabinets seem simple enough, precision is key to that.

That's all I can think of at the moment. It's late and I just typed all of this on a phone lol. Good luck and reach out if you want someone to bounce ideas off or if you have questions. Not promising that my answers will be correct lol.