- you are using wireless (bluetooth) keyboard [and mouse] in addition to the existing keyboard/mouse on the laptop
- I would first disconnect the wireless keyboard AND mouse and use just those as built in on the laptop; and observe if there is no stutter. If the problem persists then it is not to do with the wireless kybd/mouse it's something to do with your laptop hardware and/or operating system.
- if you prefer the size & feel of a traditional keyboard and traditional mouse rather than what's on the laptop, first get a regular USB wired keyboard and separate USB wired mouse; they will have USB-A connections. You need two USB-A female ports on the laptop to accommodate that, which you say you have. If the stutter problem doesn't happen this way then good...
- if you want to free up a usb-A female port on the laptop since you only have two, then get a cheap usb hub, does not need to be powered for just a keyboard and mouse. see link below, less than $10.
it's likely the wireless/bluetooth keyboard/mouse is your problem, they can often act flakey, for a number of reasons the simplest it could just be junk. So a usb hub is not some magical device that will not resolve such problems when the problem is either with the wireless (bluetooth) transmission between the kybd or mouse and the bluetooth dongle plugged in on one of the laptop usb ports, or any of that hardware. The cost of a traditional wired keyboard and wired mouse is minimal, yeah not as convenient as having no wires but way more problem free. With all the bluetooth stuff these days, it could be other bluetooth devices in the area causing minor interference with your bluetooth'd keyboard/mouse.
I have many of these and they work well, anything that's similar would be fine, connect your wired keyboard and wired mouse to this then this hub to your laptop:
SABRENT 4-Port USB 2.0 Data Hub with Individual LED lit Power Switches [Charging NOT Supported] for Mac & PC (HB-UMLS)