So you are serious about AI development? The SparkFun JetBot AI Kit v2.0 can help. It is based on Jetson Nano Developer Kit V3 by NVIDIA. It comes with everything you need to program it to follow lines and avoid obstacles. In addition to Jetson GPIO Python library, you get JetBot ROS, AWS RoboMaker with AWS IoT Greengrass to build connected robots.
This AI kit is available for under $250. You can get it on SparkFun.