Hello I am a first year student and at the start of the year I sign up for an extracurricular( I don't know how to translate from Romanian) which was "Competitive programming". I started working on codeforces and another Romanian websites problems to better myself. However since that in the 11th and 12th grade I needed to fast forward all the basic C++ algorithms and data structeres so I can pass my national exam and the admission exam for my university I wasn't able to focus on learning C++ for CP. Now, I work in my free time codeforces problems and participated in a few contests, but I am dissapointed in me, because I don't seem to improve. My question is how can I get better or evolve myself? Are there websites or books where I can learn or practice? Or do I just keep doing problems and learn form mistakes or tutorials?