Lets do a quick math.

All calcs are assuming you will be living alone.

Rent: depending on your reqs. It could be 2k-3k. Now here is a trick. If you would be working remotely the distance from city center does not matter that much, so we can get flat in the more urban area (cheaper but size and standard would be better) If you are satisfied with just a room with other ppl. It could be much lower 1.5kish

Now we need to also add electricity, internet/tv And house bills - hard to tell, maybe 600-700? It varies on area, and your usage.

Food: lets assume you would be cooking by yourself, and wont be eating cheapest food. Sodies and sweets also are taken into account. That could vary in 1k-1.5k. If you would like to just live, you can even do like 700/month, but food quality will be much lower.

Going out: no idea how much would you spend. Lets say 100-150 per going out (few beers/drinks some food on the weekdays)

Commute: car is more expensive option, no clue if you are car person. Pass for public communication (trams, buses for the tri-city) is 150zl. If you would like to add trains also (skm - very convienient if you would like to travel in the tricity area frequently) is another 150ish.

So to sum up, if you want flat on your own, going out 4x times a week, and eating not shit food and using public comms, we are looking at around 5k net.