New kitchen worktops

Planning to get my kitchen worktops replaced and am utterly clueless as to how to go about it. (Definitely not doing it myself btw, posting in the DIY subreddit as hoped folk here could answer my queries.) Planning to get laminate (yes, I know) as I want a budget option that I don’t have to stress too much about. Questions:

1. I want to replace my hob and sink. I understand I’ll need a gas safe person who disconnect/reconnect the hob. How does this work with the worktop replacement - does the hob fit into the worktop or does the worktop fit around it once it’s installed?

2. What do I do about the cutouts for the sink and hob? Planning to order the laminate online. Does it get cut at the time of ordering(and how does that work with measurements - potentially easy to screw it up?!) or do I find someone who can cut it at the time of installation?

These are possibly idiot-level questions but I would so appreciate it if anyone could help. Thanks.