Student pilot on solo flight reported experiencing two near mid-air collisions minutes apart involving different aircraft while operating in the traffic pattern at E63 non-towered airport.

Narrative

I am reporting two incidents that occurred within 2 minutes of each other; involving two other aircraft's at E63 airport.I was on a solo XC training mission. When on left mid-downwind of runway 22 (1600 feet MSL) for a downwind departure towards ZZZ airport; aircraft with callsign (aircraft A) announced on CTAF that it was '2 miles' out and intend to join left mid-downwind runway 22 at 45 degrees. However; aircraft A was in fact already within the traffic pattern area and was approaching the mid-downwind point of runway 22 at 135 KTS (according to foreflight). I broadcasted on CTAF that I was already at mid-downwind in hopes that some kind of action would be taken by aircraft A. No response was received and aircraft A continued to turn towards my location in the pattern. Subsequently; a tight 360 turn was performed to evade aircraft A and create separation between us.Towards the end of the 360 turn; an aircraft (aircraft B) was sighted joining the same point of the traffic pattern from above; only slightly in front of me position. No broadcast of intention was made before the abrupt and rapid descent onto pattern altitude. As a result; a significant airspeed reduction was performed to create separation between us. The only broadcast heard from aircraft B was its intention to perform at full stop when on what seems like a dangerously low base leg.It is imperative to note that both incidents occurred within 2 minutes of each other (maybe less). In an environment with intense flight training activity (E63); such absence of communications from both aircraft's have posed significant threat to other aircraft's within the traffic pattern; and perhaps; in the vicinity of the airport. As a student pilot myself; this felt incredibly dangerous. The above mentioned incidents can be easily avoided if active/proactive communications were maintained.