I've been through this confusion too and I've come to the conclusion that if you're just starting out with skincare it's better to have some kind of routine in place that's sort of about right than aiming for perfection straight away, getting confused and giving up 
To put a good but basic beginner skincare regime in place you need a cleanser (doesn't have to be fancy) and a moisturiser (that soaks into your skin and doesn't leave it feeling oily).
Then get any Vitamin C serum to put on in the morning and a low level (like 0.2%) retinol product for evening.
The retinol product will feel tingly when you first start using it and may cause a tiny bit of redness for up to 30mins. If you get anything more than this then use it a couple of times a week to begin with and build up to using every night.
So morning is something like:
- Cleanse
- Vitamin C serum (leave 10 mins to soak in)
- Moisturiser
- SPF 30 or 50
Night is something like:
- Cleanse
- Retinol product (leave for 10 mins)
- Moisturiser
There's tonnes more to learn but if you try to learn it all up front it will make your head spin!
For reasonably cheap Vitamin C get Vit C in silicone from The Ordinary for £6.
For a decent but not tooo expensive retinol get something like Retinol 0.2% in squalene from the ordinary for £5.
Don't worry too much about the type of cleanser at the moment and just get a nice hydrating moisturiser. I like Fresh rose deep hydration moisturiser from Cult Beauty at the moment and it's only £13.
Once you've got into the habit of doing this morning and night then come back to S&B and share how you've got on, what you liked and didn't like and what you'd like help improving.
Progress is better than perfection 