Can u use cards like eastern fiefdoms or street of sisters, silk to lower the cost of an ambush.

Ps sorry for all the questions just started playing and this game is a lot harder to learn than warhammer invasion.

no, you cannot. Ambush is a "put into play" mechanic, where the fiefdoms and streets can only be used to reduce the cost of a card you "play" during marshalling (there is a difference between the two that is important for certain effects and/or responses).

On that same note, fiefdoms do produce an influence value of 1, so they can be used as part of the cost to ambush in a card from your hand. Note this does not "reduce the cost." If you are ambushing in a Flame Kissed, for example, it is only one of the two influence you need to pay (kneel influence producing cards to pay in most cases) in order to put the card into play.

Can u use cards like eastern fiefdoms or street of sisters, silk to lower the cost of an ambush.

Ps sorry for all the questions just started playing and this game is a lot harder to learn than warhammer invasion.

No, those cards reduce the cost to play other cards, i.e. the gold cost. The only time you "play" characters, locations and attachments is during the Marshalling Phase, by paying those cards' gold costs. All other ways to bring characters, locations and attachments into play are "put into play"effects, and Ambush is too. The difference between "play" and "put into play" is crucial. See also the FAQ, §4.4, page 13.

And don't mind the questions, we're happy to help. Hope you enjoy the game!