Oatmilk would probably be good in a cinnamon dolce latte! You can definitely do it decaf, it has a slight effect on taste but not much. Hot or iced is really personal preference, but people order this one both ways frequently

I wouldn’t recommend the shaken espresso if you like sweeter drinks - they’re more espresso-forward and aren’t as sweet without a good bit of modification

Starbucks decaf is quite bitter for espresso, and not a worthy ingredient for someone who doesn’t like coffee flavor to begin with. Without the coffee it is milk (iced or steamed) with syrup and sprinkles, or a “steamer”. CDL is yummy either way, and I would recommend the coconut milk on the basis of it being one of the sweeter most mild tasting non dairy milks offered at the moment. If you’re not drinking dairy I’d make sure to order without the whipped cream, but it should still come with the cinnamon sugar sprinkled on top of the ice/steamed milk. If you’re ordering with steamed milk try ordering warm for a lower temperature so you don’t burn your mouth. Let the cashier know it’s your first time, and if you’re nervous for a work event, try going once before so you feel more comfortable!