  Aims. Coronal Mass Ejections (CMEs) are the most fascinating explosion in the
solar system; however, their formation is still not fully understood. Methods.
Here, we investigate a well-observed CME on 2021 May 07 that showed a typical
three-component structure and was continuously observed from 0 to 3 Rsun by a
combination of SDO/AIA (0--1.3 Rsun), PROBA2/SWAP (0--1.7 Rsun) and MLSO/K-Cor
(1.05--3 Rsun). Furthermore, we compare the morphological discrepancy between
the CME white-light bright core and EUV blob. In the end, we explore the origin
of various radio bursts closely related to the interaction of the CME
overexpansion with nearby streamer. Results. An interesting finding is that the
height increases of both the CME leading front and bright core are dominated by
the overexpansion during the CME formation. The aspect ratios of the CME bubble
and bright core, quantifying the overexpansion, are found to decrease as the
SO/STIX 4--10 keV and GOES 1--8 A soft X-ray flux of the associated flare
increases near the peaks, indicating an important role of the flare
reconnection in the first overexpansion. The CME bubble even takes place a
second overexpansion although relatively weak, which is closely related to the
compression with a nearby streamer and likely arises from an ideal MHD process.
Moreover, the CME EUV blob is found to be relatively lower and wider than the
CME white-light bright core, may correspond to the bottom part of the growing
CME flux rope. The interaction between the CME and the streamer leads to two
type II radio bursts, one normally drifting and one stationary, which are
speculated to be induced at two different sources of the CME-driven shock
front. The bidirectional electrons evidenced by series of "C-shaped" type III
bursts suggest that the interchange reconnection be also involved during the
interaction of the CME and streamer.
