Best Car Seat/Stroller/Travel System??

MicMiller33 β€’ Mom to 2 beautiful girls, Kirsten- 3 πŸ‘§πŸΌ & Lena- 18 months πŸ‘ΆπŸΌ, baby #3 due September, 2020 πŸ’œπŸ’œ
Help ladies!! I'm so overwhelmed by the thousands of options for car seats. Should I get an infant seat and then buy a larger one? Convertible? Attaches to the stroller or stays in the car?? HELP I'm so clueless. I've searched online and read reviews but I know this community will have some great advice. Ready, GO!!!