My suggestions, in no particular order:
Advisers
I suggest the formation of a unit responsible for the upholding of morale, discipline, and advising officers on the battlefield, but outside the chain of command. Training about morality and military strategy and tactics should be the focus of the program, and they should all be sent through basic training with the rest of the troops. I suggest at least one such specialist per brigade of 1,000 men. If we're going to create an army out of nothing, morale and discipline will be an issue and who better to take care of it than men trained specifically for the task? However, it would be preferable if they weren't too heavy-handed. No summary executions. Yet.
Questions
If we're going to be an effective fighting force, we're going to need to know what we're facing.
How is the occupying force equipped? What are their strengths and weaknesses? How does their command structure work?
As for the treaty, does it say ten battalions, ten battalion-sized units, ten thousand men specifically?
Arms and Munitions
Request equipment for eight thousand men including rifles, ammunition, and grenades. If we can get them, order one hundred civilian trucks for transport of supplies and troops. We will also need machine guns, so order two hundred heavy machine guns (if they have any) and eight hundred light machine guns. so Once we get the equipment, evaluate its strengths and weaknesses. With this information, we can develop our own weapons.
We should also ask for some scout aircraft if we they are available.
Overall Strategy
If we cannot have a standing army of more than ten thousand men, we will need force multipliers in the form of aircraft, armor, and special forces. If we can create a combined-arms fighting force, we will have an army the likes of which the world has never seen. Considering that the world considers aircraft largely useless, taking advantage of their potential before anyone else does will grant us a huge advantage. Taking the initiative like this is the only way we are going to get anywhere against such a superior force, because we cannot allow ourselves to get caught up in the grinding attrition of trench warfare considering our small population.
Since we do not currently have the capacity to do that, institute a one-year draft in order to get people military training. If we cannot have a large standing army, then we will have a large body of citizens ready to form one in short order. In addition, if there are any laws regulating privately-owned firearms in the country, relax them. If we are forbidden from doing so, fail to enforce them. Even an untrained citizenry armed with rifles and shotguns will cause a massive pain in the ass to an occupation force when war comes, and will severely damage their mobility, morale, combat effectiveness, and ability to hold terrain.
See if we can't poke the Foreign Relations people into talking to other nearby countries as well.
The Army
The army will be organized as:
5,000-man regiments
1,000-man brigades
200-man companies
50-man platoons (each platoon with one machine gun squad with 2-3 LMGs)
10-man squads
5-man fireteams for urban combat
Standard infantry brigades should be broken up on the company level as follows:
One command company
Three infantry companies
One support company containing an infantry platoon, medics, a mortar platoon, and an armored car platoon with nine armored cars for use in scouting.
Considering our current lack of equipment, our first brigades will be without mortars or armored cars, though hopefully the MG orders will go through.
With the current lack of real armor, a light armor brigade will be made up of 180 armored cars with necessary logistics and could be used as an impromptu "armored fist" on open terrain as well as for infantry support. In addition, we will likely have only one full-size regiment in the beginning, probably belonging to the infantry.
Research
Being the Minister of Defense, I propose that we found the Defense Research Institute in order to take care of the technical aspects of things, and put someone who knows what the hell they're doing in charge. Any new prototypes should be tested by soldiers in order to get their input, which will greatly help the development process. If the DRI has no ongoing government projects, give them funding and tell them to be creative.
Their first project should be to design a four-wheeled armored car.
Specifications:
Designation: M5 Cobra Armored Car
4x4 Wheeled Suspension
2 light machine guns, double-mounted in a turret with a 360 degree field of fire.
Armored against rifle fire (10mm hardened steel flank and rear armor, 12mm over the engine and turret)
Minimize use of bolts and rivets in construction to prevent spalling
Engine mounted in front to protect the crew
3 Crew (1 gunner, 1 driver, 1 commander/navigator)
Top Speed: 60-70kph road speed
Range: 250-300km
Mass: 5 tonnes
M5A Cobra
Same as above, but with a single HMG mount in the turret in the event that we go up against armor. .50 cal M2 machine guns were designed and used for this purpose in WWI.
Tell them to focus on reliability, mass-production, and off-road capability and give them some funding.
Construction
We're going to need a munitions and vehicle factory, so build them.
Strategic Situation
Where are the occupying forces based? Do they send out regular patrols? Where might we mount an effective attack?
Conscription
I suggest a 1-year mandatory military service period, though our advisers should have a five-year service period at least. Our standing army will be formed from the top 10-20% of the conscripts and will be paid more and also have access to the newest equipment. We'll need MPs as well, so once they're formed give a company to the DMAC (Discipline, Morale, and Advisory Corps)
If we hit a budget crunch, focus on the equipment and construction, but we don't have to do this all at once. We are already occupied so it is relatively unlikely that we will be attacked. This means that we can bide our time. Building up too quickly will raise suspicions and potentially cause friction.