What do these verses mean regarding today's church?

Notice that Peter stopped short in the quotation of Joel in Joel 2. He did not go on to apply this to the second coming of Christ. He applied it only to the first coming of Christ and Peter said "this is that" meaning Pentecost was the fulfillment of that prophecy.

Second, notice what He says He will do to "all mankind" versus what "YOUR sons...daughters....old men....young men" will do. Salvation has come to the Gentile world (Acts 1:8) but a particular fulfilled prophecy has come the JEWISH nation during the apostolic age. Isaiah also predicted this particular manifestation of signs and wonders performed through the disciples of Christ in those days when the Biblical Canon was finished by "my disciples":

16 ¶ Bind up the testimony, seal the law among my disciples.
17 And I will wait upon the LORD, that hideth his face from the house of Jacob, and I will look for him.
18 Behold, I and the children whom the LORD hath given me are for signs and for wonders in Israel from the LORD of hosts, which dwelleth in mount Zion.

Notice that Biblical revelation was to be finished (v. 16) "among my disciples" and the next revelation from God is Christ coming from heaven (v. 17). This is the precise order given by John in Revelation 22:18-20. The new Testament is "the testimony" of Jesus (Rev. 1:3) and that he seals up this testimony by this last book (Rev. 22:18-19) and the next revelation from heaven to be expected is the coming of Christ (Rev. 22:20-21).

However, in the last days, what we are to expect is a very deceptive miracle wonders and signs movement (Mt. 24:24-25; 2 Thes. 2:9). This characterizes the last days apostasy revival of miracles signs and wonders. In direct contrast, the Lord asks the rhetorical question "will I find faith when I come" (Lk. 18:8) showing that the true state of faithful Christianity in the last days will be relatively small and minor compared to the corrupt and counterfiet professing kingdom of God.

 

peter seemed to be quoting Joel as being fulfilled in the ears of those that he is speaking to about Yeshua...

might be true of when the Lord Jesus returns at His Second Coming, with the kingdom in full being established on the earth, as some have seen it, but that contridicts that when he returns, all need to so those things will be no more!

Don't see it as a promise to the church ongoing from Acts..

 

Partial fulfillment of Joel's prophecy in Acts 2. Will be given to evangelistic Jews during the Tribulation in order to fulfill the Great Commission (after the Rapture of the Body of Christ).