It would be useful to know if you're in the beginning of the age or at the end during an Invasion Crisis.
In the beginning of the age, I take a different approach than some of the posters here - I very rarely (almost never) train military units early on as it's very uncommon to experience heavy raids in the beginning.
Instead, I only train Scouts - how many of them depends entirely on when I can build a Granary so that the Granary finishes on the same turn as when (or the turn after) the City grows to size 4. Then I start building Settlers.
I typically always choose Gold from the Goody Huts if available, and keep around 200 in the bank in case I have to buy military units to defend myself. In case I spot an incoming raid, I first buy a Slinger to sit in the City and sling rocks at any intruder (perhaps also a Warrior if I can afford it), and if it's a considerable raid and I'm out of money, I start training a unit in the Capital.
One fortified Warrior defending next to the City Center, with a Slinger inside the City, can really do some damage!
I'm not sure whether this is good advice for a beginner or not, just thought I'd chip in with a different point of view. I always play on Deity or higher difficulty.