Do yourself a favor and beat it already!

I feel like this a time for an intervention.  My first question for you would be: which first boss?  We can get through this together.

The giant lizard thing in that pool of liquid (can't remember if it hurts you it has been a bit since I played it) stuff keeps flying at you, I think you have to jump on stuff to reach him.

To me this sounds like you are describing the playable prologue to the game where you first encounter Ridley with the baby Metroid.  If so, this is an unwinnable fight.  You don't really start playing the game until you are on the planet.  I'd be really curious to hear your progress if you decided to boot up the game again.  It is free with your Nintendo online subscription after all.  

I've never finished Super Metroid either, despite owning the game as a kid (I may have just borrowed it from a friend now that I think about it). The game actually used to be quite scary to me, so that's why I didn't play much when I was young. I was probably 14 or 15 when Metroid Prime came out, and to be honest that game scared me a bit as well, but I still managed to beat it multiple times, and I was obsessed with segmented speedruns and sequence breaks for awhile. My username on AIM was FissionMetroid.

There are quite a few in the Metroid series I have yet to finish. Metroid, Super Metroid, Zero Mission, the original Metroid 2. I know that I owned one of the GBA games, and I believe it was Fusion.

For the poll, I voted Prime. The atmosphere was so great in that game and I really enjoyed the exploration. Power-ups hidden in so many places. I remember when my friend told me that you can get up to 255 missiles I couldn't believe it. And with my skill level at the time, fighting the boss of the game without enough energy tanks and missile expansions made it quite tough, such that hunting down these upgrades is very much worthwhile.

Sounds like the Spore Spawn to me.

Which of these is the guy you were fighting?

^This is Kraid, I kind of think your description sounds like this, there's no pool of liquid but he's a two story boss and the first floor he's in a pit of spikes and fires his belly button spikes at you, and you have to climb to the second story and get over the belly button spike missiles to reach his weak point in his face, plus he has little claws flying at you.

^This is Ridley in the prologue, he can't be beaten.

^This is spore spawn, those little floaty things you see there get even more numerous, and he swings around and occasionally opens up, and you have to jump to get to his weak point.

^Just for good measure, here's Crocomire, this one has a pool of liquid, and you have to jump to hit his weak point, but not too much stuff is flying around.

I think it was Kraid he was referring to, like Mzuzek said. I was just trying to match it to what I would consider the first boss or bosses were and it didn't match so I mistakingly went to Ridley.

Kraid can be tough, but I think he's way more intimidating looking than difficult. There are a lot of moving objects to worry about and if you're not very well versed in the controls falling onto the spikes can just be a pain. I will say this to @Rustuv, the Switch Online has a great saving feature as well as a rewind button. Save before you go into battle, and feel free to rewind if you make a huge mistake. It's definitely cheating, but it's just such a great game that I'd hate to see something like a boss battle keep you from finishing the game and seeing all there is to explore.

I'm constantly using the rewind function on some SNES games. It's definetly cheating... but you can't deny it's super handy. Specially for silly mistakes that costs you a lot. Or in games like A Link to the Past were many heart pieces are based on random events that can take forever for no reason. I just rewind and try again.

In Super Metroid though... I have played the game so many times I don't really need to rewind. Although Phantoon still gives me a run for my money...

BTW, did I used the money expression correctly? I heard it many times, but I'm unsure how it's constructed xD

You used it perfectly, actually. You have a few verb conjugation errors elsewhere in that post, but you got that expression spot on!