You only have to give it a single order in combat

Commanding a spirit to fight will not consume a Simple Action every turn, but a single Simple Action once, when you use one of your services to ask/demand your spirit to battle.

You will only use another action when you require your spirit to do something else, like use a specific power on someone else unrelated to your enemies (such as concealing yourself mid-combat).

Regardless, if you are thinking on ways to use your second Simple Action on the first initiative pass after already telling your spirit to fight, you have a few options:

• Move into cover, if you haven't already (and why? You want to get yourself killed?);
• Activate a focus. It's a bad idea to have them activated 24/7, and if they aren't active yet, now is a good time;
• Shift perception, so you can take a look at the astral and see possible invisible threats;
• Draw and/or fire a weapon, this may seem like a bad idea, but remember that every single attack helps in combat, and for each attack that an enemy had to evade, they get a cumulative penalty on their reaction check until their next action;
• Cast a Reckless (using a simple action and taking +3 DV of drain) spell that has a low drain value (DV). There are many spells with F-3 or even F-5 DV, so adjusting that to 4 DV and still being able to pull that spell off in a hurry is not necessarily a bad idea, lower the spell's Force if you have to, but act!
• Call another spirit. While you may only have a single unbound spirit active at once, nothing prevents you from calling another bound spirit and commanding her to fight too;