Your screenshot shows the paths tool 
not the brush 
or pencil 
tools.
If you make a screenshot of Gimp do not use your phone, take a screenshot of the whole Gimp interface like this one.
Try using a brush
Make sure the tool options are open
In the tool options enable dynamics (if closed) and choose a suitable dynamic.
Gimp 3 is quite good with tablets this quick (48 second) demo using my veikk tablet but I do use linux not MS Windows
https://sendvid.com/mfx6tn50 no audio
not the brush or pencil tools.If you make a screenshot of Gimp do not use your phone, take a screenshot of the whole Gimp interface like this one.
Try using a brush
Make sure the tool options are open
In the tool options enable dynamics (if closed) and choose a suitable dynamic.
Gimp 3 is quite good with tablets this quick (48 second) demo using my veikk tablet but I do use linux not MS Windows
https://sendvid.com/mfx6tn50 no audio