If you are shipping stuff then usually the limits of what you can bring will be based on how much you are willing to spend on shipping.
When I move international and am trying to stick within the limit of 2 suitcases because I don't want to pay to ship my things, then I usually split my packing into two parts, 1) the basics that I know that I will need and 2) the things that I would like to bring.
For the things I would like to bring, I ask myself about each item, 1) do I really use this item, and 2) is it worth the limited space in my bag that I would be willing to let go of something else that is important to me to have this in my suitcase instead? If the answer is no, then I have two boxes, sell and donate and I put the item in one of those boxes. Most of the stuff that I need to declutter gets dealt with that way but for the small amount of stuff that I am unsure about (and usually very sentimental about), I either have to be willing to remove something I think I will need to make space for the item or I just acknowledge I feel sad about letting go of that item that meant a lot to me. I have found it really helpful to pass the useful and in good condition stuff onto people or charities who need it, it takes the sting of the loss away.
An example of the basics that I know I will need are:
To enter the country - Important paperwork, passport, ID, birth cert, work visa, regular and international driver's license, travel insurance, plane tickets, covid test results, vaccination status, face masks
To pay for things - bank card and credit card that work in the country I am moving to, some local cash, bank cards if I am keeping my accounts open in my home country, my current cellphone if my online banking is tied to this (do not cancel your phone if your banking is tied to it because the bank will block you from logging in), also make sure the phone you have works on the networks of not only your home country but also the country you are moving to
To wear - weather/season-appropriate clothing and underwear that doesn't require special laundering or care, footwear that is comfortable to walk in on different surfaces
Toiletries/cleaning/first aid - toiletries that I normally use during the week, small container of laundry soap so I can wash my clothes if needed when I arrive, small container of dish soap, a roll of toilet paper, bandaids, medicines I would normally have on hand (you don't need to bring a lot, it is just to give yourself enough time to get acquainted with where the local grocery store and pharmacy are to buy the local version of these items when you run out)
Household stuff - a few empty garbage bags and/or lightweight laundry bag, comfortable sized towel and face cloth, shower curtain/rings (if my place is unfurnished), dishcloth, dish towel, flat sheet (can be wrapped around a mattress as a temporary fitted sheet or used as a thin blanket), eye mask and a vacuum-packed pillow so that I can sleep well, a small roll of packaging tape or duct tape if things break, pen/mechanical pencil, sharpie, post its, a few ziploc bags (1 quart or larger). For most of the household stuff like dishes, furniture, etc. it is better to buy local at a thrift store or a household goods store or online like Facebook marketplace. If you are in a country with an Ikea, you can buy their basics to start out for fairly cheap. You could also look into renting a furnished place so that these basics are provided.
Electronics and tech - phone/charger that works in the country I am moving to, computer with power cord and an international plugin adaptor (you can buy a second power cord with a plug that fits the outlets when you arrive in the country, just go to a computer parts store with your computer model information), back up portable hard drives of my important digital information (photos, documents, music, etc), portable power charger (in case my phone dies and I don't have a place to plug it in and charge it), a few spare USB charging cords. If the country wattage is different, then I would buy other electronics locally.
Sentimental/favorites - moving to a new country is exciting but change can also be a lot to deal with once the novelty of your move wears off, so if you have a favorite food or pictures or item that will comfort you, then bring it, but if it is fragile and would break in travel or if it gets stolen and that would be devastating to you, then it is better to take a picture of it and leave it behind. I have friends from the UK that move a lot and bring a big box of English tea. For myself, I have a favorite thin cotton blanket that I bring wherever I move.
Moving to a different country and setting up a new life takes time. There is value in only getting things as you need them instead of buying stuff for the what-ifs when you arrive. If you can take your time to observe and learn about the new culture you are living in and how things are done there, then you can determine if you really need all the things you think you may need to live there versus what you actually need to have a good quality of life.
Hopefully, this info helps answer some of your questions, I wish you the best on your international move :)