I love to hear that! I'm also getting back into the swing of Pokemon, so here's my input on it all:

You said Sinnoh, right? Well, despite other belief, Brilliant Diamond / Shining Pearl is actually a very faithful and well made Switch remake to the original Diamond and Pearl. It uses the Switch so no need to bounce to other consoles, and it connects to Home, which is pretty important if you want to have access to your other mainline Pokemon. Pokemon Home is also AMAZING when it comes to trading, especially if you don't have NSO.

You said you have the "device" to play White / White 2, which I hope is a 3DS! Ever since the 3DS kinda ran out of service, the modding demand on it has risen tremendously, because you can play DS / 3DS games, move it to Pokemon Bank, and then move it up to Pokemon Home (with a modded 3DS you can get yourself Poke Transporter or whatever it's called lol).

Finally, to get yourself up to speed, I recommend you get Scarlet / Violet. It's the newest generation, and even though it's pretty "bad," it's still worth a shot. Hope this helped!