Advice on how to care for RC Car

Hi im kinda new to this since the last time i had a rc car was like 5-7 years ago when i was like 12. I just bought a new RC Car and spent a bit more money than i normally would but im just looking for advice on how to take care of the car and the battery and if i made a "good choice".

My first RC Car was this one:

https://preview.redd.it/958k216czwad1.jpg?width=1600&format=pjpg&auto=webp&s=5aa4ca177e10bd8aefdadb74973838ea65437fa7

the neo fighter buggy. i loved and still love this rc car. i still have it and it works fine after some tuning i did after buying my other rc car. sadly all 3 batteries for this one 3600mAh Lithium NiMh batteries died so i had to buy a new one at that RC car and plane shop i go to everytime i want something for my rc car.

the new rc car i bought from the exact same shop is this one:

https://preview.redd.it/8gmiggyqzwad1.jpg?width=800&format=pjpg&auto=webp&s=4ccb601eccb29ea464922460cab0d75b3920fb2e

the rustler 4x4 ultimate from traxxas. it does go up to 104km/h and its good for offroad use and for a bit muddy terrain which is perfect since i live in an area where the streets arent that well built and its oftentimes rocky, dirty and muddy. but im not sure if its good for its cost. i also bought a 5200mAh 7,4V Lithium Lipo battery along with it. but i dont really know how to take care of them correctly. i know that i cant let them run empty or else the battery might die quickly.

any advice?

thanks for the help in advance :)