If the bike you're looking at is the Bianchi SLR 400 on Trendyol, then that's a fine bike to start on. The listing there doesn't say what the crank (gears directly attached to your pedals) gears are, but I would assume 50-34. The cassette is 11-30, which should give you a decent range of gears for flat to mildly hilly. If you live somewhere with steep hills that you'll be riding regularly, I'd change to a wider cassette, like 11-34. But for your typical roads, 11-30 is quite good.
How many KM are you planning on riding per week? Per year? Are you going out in all four seasons, wet/cold and dry/hot? If you plan on riding a lot (say, >2k km/year), you might find some value in looking at bikes equipped with Shimano Sora, rather than Claris. Claris is fine, but Sora will shift a little better and is likely built a little better for heavier use. Of course, that comes at a price.
Just a few things you're going to want to factor in when you get a bike and start riding more than 30-60 minutes at a time:
- Get a saddle bag, and fill it with two tire levers, a tube, a patch kit, and a CO2 canister. If you can't get a CO2 canister, then get a mini pump to mount to your bike
- Learn to repair or replace your tube - you say not all roads are good, glass and rocks can easily cause a puncture. Fixing a flat tire by replacing or patching a tube is a lot more fun than walking 10-20km until you can get a ride
- Also, once you're riding more than 60min regularly, might want to look at cycling shorts or clipless pedals. Not everyone's taste, but they do make longer rides more enjoyable
- If you're looking to save weight on your bike, the first, and most useful upgrade will be the tires. I know nothing about Chaoyang tires, but I doubt they're lightweight or fast rolling. Switching out to a moderately priced folding bead tire such as Continental Ultra Sport Folding or Vittoria Rubino Pros (among others) could save you 0.5 kilo.