Our meals on the nights of Rosh Hashanah, are enhanced with specific foods that represent their respective good qualities. Because the beginning is so potent and ominous to forbearing, we thereby accompany the specific foods with prayers for the New Year.
What is the symbolism of sweetness?
It is customary to eat sweet foods and have foods with a sharp, sour, or bitter taste. This should be a siman - an omen - for the coming year that it shall be a sweet year.
Sweetness of a food does not necessarily change its nutritional value or composition; however, the desire to eat something sweet and palatable prevails. So too, although judgement is being passed, and we know that we cannot avoid His judgement, Hashem grants the ability for the judgement to be sweetened in a way that allows us to gain the ‘nutritional value’ and benefit of what He would like us to perform and accomplish in this world, yet in a way that is sweet and palatable.
Even more than the symbolism of foods eaten, one should be careful to exhibit a calm demeanor, not get angry, and just be happy, as this also portends the future year.
Why are there different orders of the simanim?
One can find two different orders for the simanim, one based upon the preference of order of blessings in general, and the other based on the successive order of vanquishing our enemy. Either way is good, and it is preferable for one to follow their custom.
Should each one recite their own beracha on the simanim?
It is preferable for everyone to fulfill their obligation with the beracha of the leader of the household. When many people do a mitsvah together, it is a greater Honor for Hashem, as the pasuk says "be'rov aam hadrat melech" – with more people performing a mitsvah together, it is the splendor of the King. If one wishes to recite his own beracha and not with the baal habayit he may do so.
Why should we have a shehechianu fruit on the second night?
All holidays outside of Erets Yisrael are each two days due to the sanctity imposed by custom of when the new month was determined by witnesses. Within Israel, all knew the determination of which day was Rosh Hodesh through messengers. However, outside of Israel, as it was distant, it may not have been known for a while, so two days of Holiday were kept. This custom created a holiness to this second day, and even after the system of set Rosh Hodesh was instituted following the Bet Hamikdash, the holiness of the second day continues with us. Rosh Hashanah, because it falls out on Rosh Hodesh, even in Erets Yisrael was not known around the country until after the holiday. Therefore, this same custom of two days had been rooted even then. Furthermore, the two days of Rosh Hashanah are of great symbolic nature, inherently considered like one long day.
When it comes to reciting shehechianu, we recite it also on the second day of each holiday. However, in consideration of Rosh Hashanah being one day, technically, one should not recite it on the second day. Therefore, the preferred way is to have a new fruit or a new suit or something with which to recite shehechianu in conjunction with the second night of the holiday. If you do not have a new fruit or new suit for the second night, one can still recite the blessing of shehechianu.