If you just come to Taiwan for #COSCUP , you may look for some natural tourist spots …
Here are some should not be too difficult to get there:

象山
https://maps.app.goo.gl/kCwFDuDotTYE2abU7?g_st=ipc

軍艦岩
https://maps.app.goo.gl/7VBXBbr7rwLwuDB29?g_st=ipc

芝山岩
https://maps.app.goo.gl/DMXnQ6ai7Uo8cNSz7?g_st=ipc

Or you can ride a bicycle from Guandu to Tamsui.
https://maps.app.goo.gl/pzvuvk6km53PY3LC7?g_st=ic

Here is also a first timer guide from people come to Taiwan :
https://github.com/COSCUP/Welcome_Taipei
https://github.com/rubytaiwan/taipei