Starting programs and scripts are controlled by systemd with Unit files. With it you can define the needed environment to run the program. But because we know nothing about your scripts and what they are doing I can only suggest a general template to start a script with GUI. Create a new service with:
rpi ~$ sudo systemctl --force --full edit node-server.service
In the empty editor insert these statements, save them and quit the editor:
[Unit]
Description=Node Server
Wants=graphical.target
After=graphical.target
[Service]
Environment=DISPLAY=:0.0
Environment=XAUTHORITY=/home/pi/.Xauthority
WorkingDirectory=/home/pi/Desktop
ExecStart=/usr/bin/xterm -c /home/pi/Desktop/startNodeServer.sh
[Install]
WantedBy=graphical.target
Enable and start the new service with:
rpi ~$ sudo systemctl enable --now node-server.service
Check with:
rpi ~$ systemctl status node-server.service
Create and start just a second python-scanner.service for startPythonScanner.sh
in the same way. Maybe you have to define Wants=node-server.service
and After=node-server.service
in its [Unit] section. If it doesn't work you have to look what additional environment settings are needed or you may elaborate your question.