You can just put 2 pistons on one side and if you want a 2 block path or room entrance you can put 4 pistons (two pistons on each side) Then you can place redstone on top of a block behind the sticky pistons. If you want a "presure plate entrance" you can place them in front of the block you placed for the sticky pistons to move. Then connect the redstone to the presure plates, or if you want something else to activate the pistons you can place redstone activators such as, buttons, levers, ect. The pistons should activate and connect the redstone to the "redstone activators" how ever they fit in. Use redstone repeaters along the redstone path f it doesn't go all the way along the redstone path.You can just put 2 pistons on one side and if you want a 2 block path or room entrance you can put 4 pistons (two pistons on each side) Then you can place redstone on top of a block behind the sticky pistons. If you want a "presure plate entrance" you can place them in front of the block you placed for the sticky pistons to move. Then connect the redstone to the presure plates, or if you want something else to activate the pistons you can place redstone activators such as, buttons, levers, ect. The pistons should activate and connect the redstone to the "redstone activators" how ever they fit in. Use redstone repeaters along the redstone path f it doesn't go all the way along the redstone path.
Here you go!