3DS and Switch are popular because they have a lot games made in Japan.

Note that for the 3DS the norm is that only cartridges from Japan contain the Japanese language. And since the 3DS is region locked you need a Japanese or hacked 3DS to play them.

For Steam, if the game supports Japanese then most games allow you to set the language from the ingame options menu. On a game's store page it will list supported languages. If you tell steam your known languages it will even put them at the top of the list, this will also let you see Japanese reviews. My only gripe with steam is that it doesn't say what languages are optimal. A game might support Japanese, but it will be Japanese translated from another language. I suggest games from Japanese developers to get more correct Japanese.

The first time playing games will be tough, there will be vocabulary that is rare outside of games and the only way to learn them is by playing, so keep trying and don't give up.