cash a cheque

i have no bank account just sold a car got paid by cheque where and how can I cash it

a pawn shop or bureau da change should do it if the bank refuses, although it might be a problem if the cheque is crossed and they will charge commission. Maybe see if a friend with a bank account is able to get it cashed
You should also be able to lodge it to an account in the credit union or post office

Have you details of who bought the car from you. Not sure it was best to accept cheque as you would not have a guarantee for it. Bank draft would have been better.
With regard cashing it - the bank from which the account is in should cash it for you ie, if was drawn on a BOI account go to BOI to get it cashed, once there is sufficient funds in the account of the payer.

I would have insisted on a bank draft regardless of if you have a bank account. If cheque is crossed you will have to open one. What if cheque is cancelled?

If the cheque is crossed A/c payee only and payable to yourself, you're unlikely to be able to cash it and you can't transfer it over to someone else.

If the cheque bounces, either as payment stopped or for lack of funds there is little you can do

I'd also be reluctact to accept a draft, especially from complete strangers, there is a known and long running scam in Ireland of cars being sold by private dealers and the seller getting a worthless counterfeit draft

You could call to the bank where the cheque was drawn and ask them to exchange it for a draft if they refuse to cash it. You will then find out if there are funds to meet the cheque or not. If there are no funds they will have to put the answer "refer to drawer" on the cheque.

Incidentally reading your one other post, how did things fare out with furniture in the end? Did you not have a bank account when you were working and had a mortgage?