(New to magic) Differences between “summon creature”, “creature” and “spells” | tcgmode

I’m new so I don’t really know a lot to anything about MTG and I’m trying to make a blue + black deck cause I like the aesthetics I’ve just collected a bunch of cards from my grandad so a lot may be old etc. Basically I’m confused on if “summon creature” is a spell or a creature and the different...