Our first son was born 6 weeks early. Congratulations! It's a shock though and we learnt a lot in the first year. It's always important to consider their corrected age when thinking about milestones etc. even when they meet them in line with their actual age. Our son didn't smile until he was 11 weeks (5 weeks corrected) but then did everything else on time/earlier in line with his actual age. But they're all different and it's important to consider those 6 weeks if he is a little slower than others to meet milestones. They're having to put a lot more effort than full-term babies into feeding/growing etc. so it's not just the missed time inside that is a challenge for them.
The other thing to remember is that the prematurity doesn't disappear when they get a bit older - there might be things that last for a bit and could be linked to prematurity. My little boy was always susceptible to chest infections in his first couple of years and ended up being diagnosed with asthma later on (no asthma at all in our families). I know other 'ex preemies' (i.e. older than 2 now) who still get a bit more tired than their peers, are still smaller etc. Again though, some babies are completely different and never show any lasting signs, it's just important to consider when they're little.
The 2 things that you always do in line with their actual age rather than corrected are immunisations and weaning. The Bliss weaning guidance is to wean prem babies between 5-7 months (actual age) and NHS guidance is to wean at 6 months actual, so that is a decision you can make based on his development at the time. But it's important to remember that prem babies don't always tick all the traditional boxes for weaning (e.g. being able to pick up food and take it to their mouths themselves etc.) so may not 'look' as ready as other babies. It's still important to wean at the right time though.
Good luck and congratulations again xxx