How to connect 2 or more external drives on my MacBook Pro?

mfzaroni wrote:

but I can only connect one at the time. If I plug a drive, the other is ejected to give place to the current and last plugged drive. MacBook Pro mid 2017 Ventura 13.6.7

What, exactly, are the two external drives? Makes, models, USB, Thunderbolt, formats? Any USB hub or cable adapters involved? Any other TB or USB devices involved?

Your MacBook Pro mid 2017 has 2 Thunderbolt3/USBc 3.1 ports. You should be able to connect a drive to each port.

You can use two external drives at the same time, but you need to stop unplugging one whenever you plug in the other.

I don't know whether you have the version of the 13" 2017 MBP that has two USB-C (Thunderbolt) ports – or the one that has four USB-C (Thunderbolt) ports. Either way, if you are constantly running out of free ports, you may want to look into an external hub or dock. There are many options here, ranging from simple USB-A hubs which provide 4 or more USB-A (USB 3.0) ports, to USB-C docks, to Thunderbolt docks.

mfzaroni wrote:

I’m using a hub to connect two USB external hard drives on my left thunderbolt, and the other one is with the charger plug. One drive is a WD my passport 1tb and the other is a Seagate 4tb

That's probably the reason for the ejections. If you MUST use a hub, get a powered hub and connect both drives to it as well as the USB power cable. Better, get a power supply for the bus-powered drive(s). Best if you don't even use a hub in the first place.