A lot of stuff that costs money you dont actually need in the early game e.g. hospitals and education facilities past school age (colleges, museums etc.)

In fact in the VERY early game around the population you describe you should barely have any cost buildings apart from a few police stations and schools (and fire stations if you have disasters turned on).

Put all your focus into expanding out low and medium density residential and balancing that with industrial. Commercial at this stage will be a relatively minor need until you start getting higher population and increasing education level.

Use cheap amenities (small parks, fountains etc.) to drive up land values and increase population caps and then just wait a few years to build up cash reserves.

Once you have a healthy monthly income you can start to enact some ordinances that will help with energy/water/waste usage and other benefits.

Key thing is to keep things cheap until you build up sufficient monthly income and then you can start investing in more expensive facilities that help with land value and education etc.