You can't MAKE one, but you can collect lava with buckets.
Two ways.... 1. Water source block hits lava source block. 2. Place redstone on a block of dirt with water flowing right up against it but not over the redstone... then let lava flow onto the redstone.
you put the source block of water somewhere where it will run onto lava then it will form obsidian. you were asking about minecraft right?
You could make a mould using any block that can't catch fire, and create the portal block by block first by pouring lava from a bucket into the spot you want the next obsidian block to be, then using water to turn it into Obsidian.
If you have a bucket, manually dig around underground until you find lava, then get reasonably close with your bucket and right click. Your bucket will fill with lava. Move back to your place, then rightclick on a block to place that lava. Be careful, as the lava you place will being flowing down. Also, lava burns close-by wooden things.
Hard Way: Look deep and find it naturally. Easy Way: Put Lava and Water together, but make sure the water flows into the lava, and the lava is not moving when it touches water, or it will make cobblestone. Note: Lava flows slower than water! So make a 3x1 hole 1 block deep, place a nonflammable block in the middle (cheap stuff like dirt or sand. NOT WOOD OR WOOL!), put water on one side, lava on the other (using buckets), then take away the block in the middle (and the lava becomes obsidian). Then you pick it up by using a diamond pickaxe.
Lava or make a hole and they "fall" through it
look it up on minecraft wiki, it really depends of what light, whether it is fire, glowstone or lava.
there is no "carpet" item/block in minecraft, but people use different colored wool as carpet for minecraft.
no, it depends on the type of bridge
type /water or /lava
Diamonds are located near a natural lava source. Making your own lava source does not magically make diamonds appear.
It cannot be "made" unless you destroy a block, creating air in its place. Otherwise, it is just another term for the lack of a block in the minecraft world.