Never built a kitchen cabinet in my life, time to learn how being that’s the next major step.
Alright then. I can tell you how we did ours. Like you, it was a first, and building one was fun. Building the other 18 sucks. It gets old fast. My advice is to find an extra day or two of job somewhere then go to Lowe's and buy them.
So starting out, we built the main box out of cabinet grade plywood. Cut a toe relief out of the bottom buy cutting a notch. I like to use a dado head on a table saw so that the back and bottom pieces slide in. That holds it straight and square, but not required. Glue and finish nail it together. Notice in the picture how the back is inset from the wall since it runs in a dado on the side pieces. If your walls aren't perfectly flat, then this relief lets you push the cabinets up to the wall without rocking back and forth. Research how tall you want your counter top to be before you start. Everyone is a different height and build them so they are comfortable to you and yours. Visit friends and measure their junk.
Then build the face. We used precut style boards. Miter saw them to length. We then used a biscuit jointer to put them together with glue and clamps. Once dry, finish nail them to the box using glue and clamps.
Cut a toe board if it is a stand alone cabinet, or wait until they are all put in place next to each other and run one toe board across multiples to tie them together.
Be sure to put a board across the front and back at the top for your counter top to screw down to. Screws will come up from the bottom so you can also predrill them with a countersink bit if you want.
Next, we used a rail and style router bit set from Lowe's (like $100) to make the cabinet doors. This gives you a dado on the inside edge for whatever you want in the middle to fit into. You don't have to go this fancy but it is worth the bit cost since the groves will hold them together nice and square when you glue and clamp them.
I know a schit ton more about woodworking than I know about being a diesel mechanic feel free to holler anytime.
Your drawer slide selection will determine how you build your drawers. The ones we used were simple to use. Build your drawers with a 3/4 thick face panel and then dado your drawer together. We used 1/2 ply on ours.
Remember, you can't put a drawer in front of your kitchen sink. They make little flip out deals for brushes but we just covered ours solid.
Funny how I can't find any pics of them completed with the top cabinets as well. Here is the bottoms mounted.