Crisp white, light blue and faded light pink are all classic staples that look greatwith a navy suit. White is the most formal and I'd consider it the most appropriate for a wedding. Avoid dark or garishly coloured shirts. Avoid striped patterns (it will clash with your suit). Other patterns are ok as long as there's a strong visual distinction between your jacket and your shirt. Normally I'd prefer a french cuff for a wedding, but pairing french cuffs with brown shoes is pretty grim. If the shoes are brogued wingtips, avoid french cuffs like the plague. I'd strongly prefer a shirt without a pocket for a wedding, to remove it from the office-world and towards more graceful attire. Especially encouraged with your pinstriped suit (a very business-like officey pattern). These shirts and a navy suit provide a brilliant base for any number of ties, with darker (non-black) ties being the most "classic" (e.g. burgundy, navy, forest green, chocolate brown). For a wedding, however, consider the value of ties with greater levity and joyfulness. Again, avoid garish colours and crazy patterns. Soft medium blue could be very nice, or perhaps not-too-light pastels and silvers/greys with houndstooth/check patterns are a classic wedding tie . Lastely, consider the value of a smart white linen pocket square to bring dignity to the suit and/or a boutonniere as a classic, celebratory and festive addition. More on reddit.com

The top part fits a little loose. Though I would imagine it's quite difficult to find nice suits designed for women and in women's sizes. Especially at an affordable price. :'( You still look great though!!!!!! More on reddit.com

The Kate suit in the first pic and the first one shown for Letizia are my favorites, they look so chic. More on reddit.com

There isn’t any rules against it but it’s pretty hard/tricky to do. More on reddit.com