Changing from domain forwarding

to the normal way of having your domain point to your hosting. What happens to my blog post links? I have no idea what I am doing.
Basically I had free hosting with isp, which meant I didn’t have the IP details to give my domain admin…I had to redirect instead. That has totally ruined my google presence.
Anyway I’ve now sorted it out, have the details of where to point my domain too. My hosting is still in the same place. I have no idea what happens when I do enter these details.