1) StackExchange is really not intended for the side-by-side mentoring it seems you are looking for. It is a good place to ask questions about specific problems you run into.
2) Python is not the programming language I would recommend for the real-time control needed for a robotics/mechatronics project, especially for a beginner. I recommend you start with something simpler like Arduino. If you need more advanced features, you could later add an Android phone that talks to the Arduino. This is becoming easier as Android Studio is free and picking up an obsolete Android phone can be really cheap. Android phones have a lot of advanced capabilities like a user interface, a display, GPS, accelerometers, cameras, and WiFi. You could even use a 2nd phone as a remote control by using WiFi Direct to talk to the Arduino on the robot.
3) Look locally for a mentor/club. Depending on your location and age, you could find a High School robotics team to join, maybe take a class at a local university, or find a local robotics or 3D printing club. If all those are not a possibility, consider building a heavy DIY kit. A really good option is buying a 3D printer then building a 3D printed design.
Ex: 3D-Printed Arduino Spider Robot
4) Get a 3D Printer or at least find a way to access one! I mentor a Robotics Team and 3D Printing has been a huge advance in helping me develop the students. It allows them to take their ideas to reality very quickly and learn what works and what doesn't; and, when something doesn't work it allows them to quickly modify their design and try again.
5) Accept that learning something like this is going to take a LOT of time, passion, and commitment. Don't expect that a mentor is going to reduce that for you. Mentors are often passionate about helping others grow; but, generally they have a lot of other demands for their time as well. If they see they are putting more effort into your project than you are, expect that they may move on to more fertile ground.