I'd agree with
@koalar; for a 2010 Panda, there's nothing there that I wouldn't expect to see, and I don't think this one is actually too bad.
Exhaust is rusted out a lot and back axis are also rusted, I am not experienced with the rust repair so best i can do clean it and cover it with rust converter and spray or buy new pieces and replace them.
Once the beam is this rusty, painting it in situ is likely to do more harm than good, You'll never be able to prepare the surface properly, and it'll just keep rusting under the paint. Water then gets trapped between the paint and the metal, leading to more rapid corrosion.
The easy way to deal with this is to wait until it's totally dry (summertime maybe!), then brush off the loose rust and smear it all over with the thickest grease you can find.
If you want to paint it, you'll need to remove it from the car and have it shotblasted to have a meaningful chance of the paint adhering properly. At least one person here has gone to the effort of having it hot dip galvanised after shotblasting; do that, and it'll be the last part of the car left standing once the rest of it has rusted away.
My experience of using rust converters is that they don't leave a surface that's sound enough to paint over. You need to strip all the corrosion off back to bare metal if you want a lasting result.
I'd just leave the exhaust until it actually fails, then replace it complete.
One thing that is worth keeping an eye on is the bracket that attaches the front part of the exhaust to the gearbox; this is often found to be in poor condition and often rusts away. You can see it in your first picture. Yours actually still appears sound, but if it gets any worse, replace it (possible without removing the exhaust), since it's needed to stop any movement of the exhaust from damaging the manifold where it attaches to the head. There aren't many 2010 Pandas in the UK that still have this original bracket, so yours is actually less corroded than most.
The sump doesn't look too bad either; wipe it over with an oily rag after each oil change, and it'll likely last the rest of the life of the car.
Actually the whole thing looks pretty good underneath; we've seen far worse here, on newer cars than this.