weed help 🙏

hey so i’ve recently started smoking weed and i have no idea what im doing. i have good friends and family so i get good shit so that’s not the problem. i can take small hits fine little to no coughing on bigger ones but today i was DAMN near close to a blinker and i felt like i was suffocating? this might be common knowledge but is it normal to feel like on the brink of death… (exaggerating kinda) also is heart rate increasing normal?