Measuring current draw on Arduino

Hello!

I am beginner to Arduino and want to make sure that I do not mess anything up so my apologies if something I say is stupid!

I am making a portable device with an Arduino Nano and a couple of modules like i2c displays, mpu6050s and servo motors and would like to make sure I choose a battery that can support portability. I tried reading each modules datasheet independently, but with some google searches, I feel like I'm getting mixed answers for current draw from each module. (Or maybe just my incompetency to understand).

And so my question is, would it be possible to run the whole setup while I have it USB powered / connected to power supply (If I decide to use an Arduino Uno) and use a multimeter to check for current draw? If this is possible, what is the correct way to measure this without ruining anything? Is there another method to check for current draw as well?

Thank you for your time!