Need help on carseats!!!

Aylin • 1 baby boy Aiden 💞 Ttc for baby #2
Okay so I really want to get a convertible car seat for my baby (due beginning of Feb) but I know with a convertible car seat it will stay in the car and we will have to take the baby in and out when we go inside, to stores etc and he won't be big enough to sit in the carts at the stores yet so we'll have to carry him throughout the store plus it will still be snowing and cold out. So my question is should I just buy an infant car seat with a base that we can carry in and out of the car, stores to make it easier? And just wait until he can sit up in the carts by himself? What kind of car seats are you expected mothers getting?!