A spy doesn't need much more than a discreet suit that will easily get him through the first obstacle and a gun, even if it's a single pistol and there is no bullet-proof vest inside. With this, knocking down the security guards one after another is enough to get their uniform and heavy guns, which is exactly when the action begins. It is not easy and death is certain for untrained spies, which is definitely not your case, almost a real life James Bond. Get yourself past the first guards and, once inside, be quick to use everything you can find to unlock secret doors and find your targets, people that must be killed without warning the others, exiting once the mission is done to start another right away. The rest will come after you die, today you will be active the whole time and finish whatever your tasks are.