Script that open a lot of instances of a web browser

Hello , i need to make a python script that runs multiple instances of a web browser . It should ask me , when i start it, how many instances of the browser it will have to run. I need to run a lot of instances probably around 300. I should be able to import proxies from clipboard or file in this format , ip:port and ip:port:user:pass. Each instance must uses own cookie , cache and ip , so they must look like done from different devices and people. The script must monitor on each page a url and notify me then on that page appears a recaptcha, the first instance that have a recaptcha must be opened so i can continue manually , then the script should notify me in background when on other instances appears the recaptcha and ask me if i want to open that instance. A really important thing is that the pages that are monitored don't have to be resfrshed.