First, I'm no expert with C++ but I have minor experience with it. But, some good resources that I have used is a "C++ Tutorial for Beginners" by Programming with Mosh and I have also used Plural Sight's online course if you are willing to pay I think around $30/month for a membership (they might have a free option, I don't remember, I haven't used this service in a while). I would suggest finding free resources though. Try to focus on working on a variety of projects using a variety of techniques to get a feel for the language. If you are looking for books, there is "A Complete Guide to Programming in C++" by Ulla Kirch-Prinz and "Accelerated C++: Practical Programming by Example" by Andrew Koenig. A mobile app that might be interesting to use is Sololearn. I don't know if you use Android or iOS so it might not be available on iOS because I use Android.

My DMs are always open for questions. I can try to help whenever or whenever I can.