If you want a free online Bible to follow along with, BibleHub is good with many versions available - my fav is BSB.
Matthew 5:3-5
The poor in spirit receive the Kingdom of Heaven! Being or realizing one is poor in spirit is generally thought of as realizing oneself is wretched spiritually and needs God's salvation. In that way they receive the Kingdom of Heaven and so can be eternally blessed with the right attitude of awareness and yearning for God's mercy.
Those who mourn will be comforted. Those mourning for lost loved ones often express how they can't be 'magically' just okay again as some things will never be as they were again. But they can have some hope that they will be comforted, perhaps in seeing their loved ones again in the afterlife or in some other ways before that.
The meek will inherit the earth. Those who remain humble and wait on God rather than take things into their own hands are promised a great and lasting inheritance!
Matthew 5:6-8
Those craving righteousness will be filled. God will answer those desiring righteousness with a full measure of it. God often rewards those desiring the right things with both what they want and even more!
The merciful will be shown mercy. I've often received extra mercy after showing it myself. But even if the mercy isn't given back by other humans, receiving it from God will still be great!
The pure in heart will see God. It may be that only the pure in heart can see or be in the presence with God. Hence why our sins need to be washed away in order to see God.
Matthew 5:9-12
Peacemakers will be called sons of God. It's likely in order to make peace one has to give up something or forego gaining something. This act of sacrifice may be what qualifies to be called a son of God.
Those persecuted for righteousness like those poor in spirit receive the Kingdom of Heaven. I think this refers to the righteousness of having sins forgiven, so having confessed our inadequateness and received salvation.
Being insulted, persecuted, and falsely accused for Christ leads to a great reward in Heaven. This goes along with having experienced the same as the great prophets in the past, so ending up in great company!