Well you can add and remove stuff depending on your path but generally this is 'Pagan New Year', the last harvest has passed and it was seen as 'winter' from here on by our ancestors. It is also the time of year when the spirits return because the veil between our world's are at it's thinnest.
It's a great time to reflect on departed loved ones. Don't try and 'summon' their spirits, but it's nice to put out pictures, perhaps make an altar with food offerings. Some people have a dumb supper [basically set out extra places at dinner for any hungry spirits who may visit during the night]
Decorations are similar to Halloween, purple, black, orange, black animals [cats, dogs, crows, bats] pumpkins, gourds, and seasonal crops can be used to decorate your altar.
Activities you could do depend on how many people are joining you. My coven does divinations and talk with spirits [pendulum or Ouija board] but you could do that on your own. An old one was apple bobbing. If you got an apple it predicted love in the coming year. You could also try this one where you bake bread and place various objects in the bread [baby, wedding ring, coin, and something else I forget] each person takes a loaf and if you get one of the items it's said to be in your future [find the coin and you could come into money in the next year] I would avoid cleansings since Samhain is a time for departed souls. Many do love divinations around this time, and you could also cast spells of this nature too.
If you want a ritual, it does depend on your path but you can find [and alter] one online to work for you.