Let me start by repeating the usual refrain when talking about what the average ancient person would have experienced: we just don't know that kind of thing. That being said, we can say a few things about the state of Rome itself at this time.

Rome would have been visibly smaller than it was in the 2nd century CE; there would be abandoned buildings. You may have lived through the Vandalic sack of 455 which damaged much of the city's infrastructure. The previous sack, in 410, would have been widely remembered. The failure of the Western Roman Army to prevent these sacks would have dramatically displayed to the population of Rome that their power was not what it once was.

The population would probably have also been aware of the large sections of the West which were practically no longer under their control, although most were still at least theoretically a part of the Empire. It's usually difficult to say when areas stopped being under the power of the Empire; in most places the Empire just sort of evaporated: money stopped coming through for the soldiers, local authorities would take more of the initiative in making decisions as the centre of the Empire became less responsive. The following was written around this time by St Severinus, who lived in Batavis near modern Passau:

At the time when the Roman Empire was still in existence, the soldiers of many towns were supported by public money for their watch on the wall. When this arrangement ceased, the military formations were dissolved, and at the same time, the wall was allowed to break down. The garrison at Batavis, however, held out. Some of these had gone to Italy to fetch for their comrades the last payment, but on their way had been routed by the barbarians. (Eugippius, The Life of St Severinus 20. 1-2 (translation L. Bieler with L. Krestan, The Catholic University of America Press, 1965)

This is how the average person is likely to have experienced the fall of the Western Empire; not as a dramatic invasion event by foreign speaking peoples, but as a realisation that the soldiers (if they were around) weren't going to get their back pay. They'd have to make do with what they had locally.

The citizens of the city of Rome definitely would have known about the loss of North Africa to the Vandals in the 430s; North Africa was the most productive part of the Western Empire and its loss would have sharply increased grain prices in Rome, as well as contributing to the loss of the tax base in the West. You may even be aware of the preparations to retake North Africa; a large expedition of both Western and Eastern Empire forces was dispatched in 468 but defeated in a naval battle by the Vandals.

I simply don't know if the average person would have been aware of the fact that the Emperor was mostly a puppet and the real power lay with Ricimer. Someone who specialises in Late Antiquity may be able to say more.

How aware was the Roman citizen of the political intrigues going on at the time? Did they know anything about Ricimer and his control of the emperors of that era?