Option 1: SAMBA
This is the high tech solution. It involves:
Step 1
Use the SMB (SAMBA) protocol in Windows 10 share all the folders you want to copy from the Windows laptop to the Ubuntu laptop. I can't help you with this as I don't use Windows much.
There are many tutorials on the Internet on this topic. Here is an example. In this tutorial, you will need to follow the option 1, and enable SMB1.
Step 2
Use the SAMBA client in Ubuntu to access the shared folders in Windows laptop. To do this, open the Files app in Ubuntu and select the Other locations on the left margin at the bottom:

Then click on the Windows Network. There you should be able to see the name of the Windows laptop. Click on that, and you should be able to see the shared folder, you shared in Step 1."
Step 3
Copy all the shared folders into Ubuntu "Home". You may want to copy the Documents, Music, Pictures, etc. in the corresponding Ubuntu folders by dragging the contents of those Windows folders into the corresponding Ubuntu folders as seen the left margin of the picture above.
Option 2: External Hard Drive
This is more expensive but easier option, as you don't have to worry about sharing folders, mess with read and write permissions, or network settings. Another good thing about this option is will will have a second backup of all your valuable data.
Step 1
Buy an external hard drive. You need to consider two things when buying a drive.
Disk Space
The drive should have sufficient disk space to store all the data in the Windows laptop. A 1 terabyte (1TB) external hard drive may be sufficient. However, you will have to decide based on how much data you need to transfer.
USB C
Your new Ubuntu laptop has only USB C sockets. The external hard drive must be compatible with this smaller sockets as you will be using the external hard drive with the new computer.
Most USB C external hard drives come with either a second cable or an adapter so that it can be used with older USB sockets (USB A sockets). Make sure the hard drive you buy has either a second USB A cable, or an adapter.
An example
This link shows an example of such an hard drive. I have never used it and I do not endorse this site or this product in any way.
WD 1TB My Passport Ultra Silver Portable External Hard Drive, USB-C - WDBC3C0010BSL-WESN
Step 2
Plug in the external hard drive to the Windows laptop. Copy the folders you need into the external hard drive.
Safely remove the external hard drive. Do not unplug the hard drive until Windows tells you it is safe to remove.
Step 3
Plug the external hard drive to the Ubuntu laptop. Copy all the folders into the Ubuntu laptop.
Safely remove the external hard drive. Do not unplug the hard drive until Ubuntu tells you it is safe to remove.
Hope this helps