You can easily find out what you might pay in property taxes when you start looking for a house or condo to buy. The real estate records for each property will show what the taxes were for the last year. Your real estate agent will be able to show you all the details. Sometimes it's all spelled out online. Property taxes are assessed according to a rateable valuation system. Challenging property taxes in Cook and Lake counties has turned into a cottage industry, and you will get solicitations from law firms in the mail. Challenges are sometimes successful.
Your monthly mortgage bill will normally include the mortgage amount, a home insurance charge if your deposit was under 20%, and a monthly pro rating of the quarterly county property tax, held in escrow and paid from the escrow account.
Additionally, if there are association fees (in a community or condo building) all of that information will be provided by your agent.
You can also get an idea of utility charges, water/sewer & garbage collection fees from the real estate agent too. Utility costs are self reported by the seller.
You sign on with a buyer's agent when looking to buy, and this person - a fully qualified real estate agent, most agents will do both buyer and seller roles though not at the same time - will take you to see properties, help you through the negotiation stage, be there at closing aka "exchange" to handle any blips, probably suggest a home inspector to do the structural inspection once contracts have been accepted, maybe even find you a lawyer to handle the legal end. The buyer's agent usually gets a fixed fee. Seller's agent usually gets a proportion of the final sale price. It would be a very good idea to make a foray ahead of your planned move to get the lie of the land, talk to agents in target communities, and even see a property or two, just so you know what you might be looking at. A real estate agent could also help you find a decent apartment, and there are dedicated relocation specialists who do this too.
Your property taxes pay for local municipal amenities like the library, parks, playgrounds, public pool(s), public ice rink, tennis courts, soccer fields, baseball/softball fields, municipal parking lots, and services like meals on wheels, snow 'plowing', street and alley maintenance, police service, any youth outreach, graffiti abeyance, and above all, SCHOOLS (including teacher salaries and pension plans, security, services within the school or school district like school psychologists, SEN provision - often fantastic ) and all the facilities and opportunities schools offer; sports, performing arts, fine arts; in many districts you are looking at what you would find at a top notch English public school without the uniforms.
Property taxes also pay for county services like the county health system, water reclamation, county forest preserves (public woods, trails, lakes, stretches of river, etc) and lots more.
Wrt cost of living, I am in an old and quirky suburb, and I have both chains and ethnic groceries fairly close at hand as well as Whole Foods (where I only buy cat food and bulk Israeli couscous), Trader Joes (where I only buy plonk). There are hispanic, Asian, Italian and Polish places I can get to quite easily. There is one particular place that has all the stuff you would find in a chain but also four aisles of 'ethnic' stuff including blackcurrant drinks, jams, Indian cuisine staples, Garibaldi biscuits made in Saudi Arabia but the real thing all the same, and other items that I wouldn't find elsewhere. Middle eastern requires more travel, though the store I mentioned carries some. I could easily spend half my income on groceries but I shop around - opening hours allow this.
The availability of a broader and often cheaper range of grocery stores is something you would find in Skokie/Evanston and the northern Chicago neighbourhoods.
Activities for kids - a season pool pass where I am costs $50 per person, and allows unlimited pool visits from end of May to end of August. A rink pass costs the same, and allows year round skating. AYSO youth soccer costs $175 per player for the upcoming 'Fall' season, plus about $20 registration fee.
An 18-class session in my local Park District gymnastics centre costs $324 for residents. The gym is purpose built, with qualified instructors. There is a private gym locally that charges $60 to $100 for a four-week session, classes from 45 mins to 2 hours, once a week. A four month swim team season in a local competitive swim programme costs from $400 to $650 per swimmer for the entire season. Lowest rates are for age 5-8, top rates are for high school boys. You could look through this to see what is on offer in dance in my area www.academyofmovementandmusic.com/wp-content/uploads/2018/02/Online-Summer-Schedule-2018.pdf. I have no idea if this is representative, but it's a superb facility and there is a huge market so they are probably charging as much as they can in a pretty well off area.