Your conservatory base will need strip foundations (which will hold the dwarf walls) to surround the base. There are several types...

Deep Strip
A type of foundation where a deep narrow strip footing is filled shallowly with concrete (like a letter T)

Trench Fill
A type of foundation where a strip footing is filled to the top with concrete, to make it easy for the bricklayer to build the dwarf wall.

Raft
Normally used on properties where the ground conditions are poor – the raft floats on the earth.

Plied
Used again in poor ground conditions, this time a piling rig drills a deep hole which is filled with concrete or the rig drives a precast concrete pile or a steel pile. These piles are then capped off with a ring beam onto which the conservatory foundations are built.

Concrete is very heavy and it needs to be laid fast. For instance a 3m x 4m slab of concrete with a depth of 100mm (or 0.1 metres) will consume 1.2 cubic metres of concrete weighing around 2 tonnes. Don't try and mix it at home as this would require a cement mixer and dozens of bags of sand, cement and aggregates. A good alternative is to use a builder to do the footings, slab and dwarf walls. If you are going for the full DIY approach then look for a "barrow mix" concrete service. These firms have no minimum quantities and they can get multiple wheel barrows of concrete to your conservatory site in no time at all (even if it is inaccessible to a concrete truck).  An inexpensive way of increasing the slab strength is to add fibres to your concrete mix, simply ask you concrete supplier for more details.