You can just use normal rolled oats, not fortified but LO is still getting nutrients from milk.
Instant oats such as Ready Brek are fortified, this is fine for baby even though it is not specifically a baby cereal, the original flavour has no added sugar. I wouldn't recommend other flavours at this point but you can add some fruit if you wanted, mashed banana, grated apple or a cooled fruit puree for example.
There is no need to begin with baby rice or indeed no need to use it at all. It has little nutritional value.
Whole grains such as brown rice/bread/pasta are not advised because these may be too filling, if baby gets too full he may not take as much milk. It's recommended to give babies white rice/bread/pasta although if you are making something for yourself and it is a small amount baby is having then it would be ok. For example I had wholemeal sliced bread and didn't buy a white loaf just for LO because he only had a small amount, but other things (pitta, naan, bread rolls, crumpets, pancakes, pasta etc) were all white rather than wholemeal.
The iron in your breast milk is readily absorbed by LO so there is no need to worry about iron stores/supplements.
Meat can be given as a finger food for baby to suck and gum on, they can get quite a lot out of it even with no teeth. If you eat meat you might offer a hunk to baby.
Dark leafy vegetables, beans and lentils all contain iron. Liver is a very high source of iron, my LO liked liver pate so I made a home made smooth salt-free pate for him and offered as a spread on bread/toast or just cut into chunks for him to eat.
In the UK there is a recommendation for vitamin supplements for babies from 6 months (it's often a liquid measured with a little dropped onto a spoon) but this varies country to country. You may want to ask your medical professional if vitamin supplements are recommended where you are, and if so which vitamins.