Yep I'm in the same position. The ruins development was finally completed this turn, so I haven't received anything from it yet but starting next turn it will churn out IP, metals and rare metals for me. Even better, my IP production is finally freed! So, decisions....
Currently 1st Inf Brigade are fairly close to the city so they can just about stay in supply, so roads not a priority yet. I happily spend the single IP, single metal and 100 reserves to bolster the battalion that lost 100 men in turn 2. Now I have to decide the best way to further develop my infrastructure. Thankfully water and food are solved problems for now, so, like Geek, I have to decide between a metal mine which requires IP, or bolstering IP production in my city which requires - yes, you guessed it - metal!
For now I decide to build nothing at all. I don't have enough IP to complete construction on anything so I'm going to let them build up for a few turns, possibly skimming a few off the top each turn to build machinery. Those machines can either themselves be used for production - saving me a fortune in purchasing - or sold for profit. Either way, building machines is a Very Good Thing. The next two developments I have my eye on will cost me around six machines in total I think, so if I build one per turn while storing the remaining IP everything should come together nicely a few turns down the line.
My long term goal will be to start building my supply network. For now dirt roads will do as anything's better than nothing, but later when I have the metal to spare I'll start building railways. With a supply network in place I'll be able to send 1st Inf Brigade all over the place, claiming territory and I'll even start thinking about where to site my next zone. I'll also need to raise a new formation, but I've never done that before and it looks quite complicated so I'll need to thoroughly read the manual before I begin.
The only problem I have left at home is I don't really have any capable personnel - certainly not a level 5 inventor like Geek has, the jammy git - and that's not likely to improve any time soon as my interior council's budget has zero BP allocated to HR strategems. So another goal is added - building up the admin buildings. More pen-pushers = more BPs.
This is the most stable start to a game I've had yet, and the first time I've really felt like I know what I'm doing. Consequently I'm enjoying it a lot.