This is one of the most simple forms of obtaining cold brew, and French Press, or by technical terms, an immersion brew.
For a HOT immersion brew, i.e., French Press, pop the bag in with 250 grams of hot water, and wait for 5-10 minutes. I like to just sip on it after 5 minutes and leave the bag in the mug to continue steeping away.
For a COLD immersion brew, i.e., Cold Brew, pop the bag in with 250 grams of room temperature or cold water, set it in the fridge, and wait 12-24 hours. Different characteristics of different types of coffee will begin to immerge at different times, I like to pop in two bags with 500 grams and have plenty of coffee for my next two mornings.
You may like to 'bloom' the coffee with hot water, adding 30 grams of hot water per bag, waiting 30 seconds, then finish with cold water. This extracts some flavors that are hidden with cold water immersion brewing. However, be mindful that this also brings up acidity.
Enjoy the exploration!