Car seats- update

My mom used to do foster care so she had lots of baby stuff she was getting rid of, including a car seat and base for infants. I’m not sure of the weight on it, but I know it’s jot like brand new or anything but it is on good condition. How important is it to have brand new car seats? Is it even worth it where you eventually need a bigger and front facing seat?? Do I need to start car seat shopping or is it safe for me to use the one I have now that I got for free??

UPDATE

Okay ladies for the life of me I can’t find an expiration date on the car seat. I did find the manufacture date which was sometime in early 2012, but I would guess by the end of 2018 it would be expired right?? I swear I looked all over that dang seat and could find no other date on it