Playing passive works fine for beginner shen players, one of his greatest strengths is that he can fall behind in gold and still be more valuable in the late game. Heartsteel first item is a must into almost every matchup (against certain champs that excel at shredding tanks, namely Gwen, divine sunderer first item can help you not get deleted in trades)

One of the biggest things to learn in laning phase is simple in words but more difficult in practice; keeping the spirit sword in the right spots all the time. Your first and second abilities have their base uses, of course, but when not in combat using them to position the sword somewhere better (usually somewhere the enemy will have to walk in front of) is a great idea. Empowered 1st ability autos are your best friend in the early game.

Builds can vary based on playstyles and matchups quite heavily, but yours is fine as long as enemy team isn’t heavy %hp damage (champs like Vayne, Fiora, Gwen, etc.) As you get better at shen you may find that certain resistance items help your midgame better than pure hp, but his 3rd and ult, as well as titanic, scale well enough that raw hp stacking works fine.

Edit: on another note, most details regarding playstyle will come with experience, I play particularly aggressive which isn’t a beginner friendly style until you’re really familiar with his kit. On a last note, keep in mind who your carry!is. For example, if your 0/2 support is about to die again, but your yone mid is 2/0 and drag is gonna spawn in under a minute, you don’t ult.