Mommie6. Have I misunderstood "the Shower"? Is it a sort of party? Like a baby-shower when people bring the expectant mother presents for her expected baby? We don't usually have these in the UK so I didn't understand. We do have a "Hen Night" but that is usually the Bride and her friends together having a night of fun and usually just for that generation. The Stag Night is the same for the future Bridegroom with all his male friends. I expect you know but I didn't understand the "shower" and thought you were having a wash!!
The other thing is the Processional. We just don't have one. The Groom is already at the altar if it's in Church, or at the desk in the Office, waiting with his Best Man beside him. The Bride comes down the aisle on her father's arm or if there is no father someone she chooses (I had to for my daughters because their father died) following the Bride are the Bride's Maids or if she chooses, Matrons of Honour and/or page boys. The Mother of the Bride sits in the front with all the other people. The Bride's family usually sit to the left as you enter, the Groom's to the right.
When the ceremony is over, the Bride and Groom walk down the aisle together with the Bridesmaids, Page Boys, Maids of Honour (if any) following them and the parents of the Bride and Groom usually file out behind them followed by their family then all friends follow on.
Photographs are usually taken with the couple, the couple and bridesmaids etc., the couple and his parents, the couple and her parents, the couple and both sets of parents and bridesmaids etc., then whatever is decided!
If you have a very different arrangement we need to know. The Mothers' flowers is not a set tradition for me. However at my children's weddings, both I and the other mum respectively were given a bouquet of flowers at the Reception when the speeches were made. I was not expecting it - to me it is not something that "must" be done!