To rank things, use better than to compare two, and the best for the top of three or more. For longer adjectives, use more + adjective instead of adding -er.
Saying one thing is better
better than /ˈbetər ðæn/ — Maya's second draft was better than her first.
the best /ðə best/ — Magaff Library is the best place for quiet study.
more /mɔːr/ — The second route is more convenient than the first.
Not ""This route is more better than that one."" — say ""This route is better than that one."". Better already means "more good," so you never add another more in front of it.
Try it: Lars: You tried three cafés. Which one for meeting friends? Amina: Ghafridge Cafe is ___ of the three. Which reply is correct? (the best / better than / more good) Answer: the best — With three or more choices you pick the top one, so you need the superlative 'the best'. 'Better than' only compares two things, and 'more good' is never correct because the word is simply 'best'.
Showing two things are alike
To say things are almost the same, use similar to (keep the to) or use like to mean "the same as". Both introduce the thing you are comparing with.
similar to /ˈsɪmɪlər tə/ — Mei's answer was similar to Hiroshi's answer.
like /laɪk/ — The new app works like a digital notebook.
Not ""This cafe is similar Ghafridge Cafe." (missing the preposition)" — say ""This cafe is similar to Ghafridge Cafe."". Similar needs its partner to before the thing you compare with.
Try it: Diego: How was today's task? Lani: It was ___ the one we did yesterday. Which reply says they were almost the same? (similar to / similar from / similar than) Answer: similar to — Similar always takes the preposition 'to' when you name what you compare with. 'Similar from' copies the wrong preposition, and 'similar than' mixes it up with comparatives like 'better than'.
Showing things are not the same
To say things are not the same, use different from. Notice the pattern is different from, not different than or different to in careful English.
different from /ˈdɪfrənt frəm/ — Yasmin's opinion is different from Diego's.
Not ""The new timetable is different than the old one."" — say ""The new timetable is different from the old one."". In careful English, different pairs with from, not than.
Try it: Sofia: Was the online lesson like the classroom one? Diego: No, it felt ___ the classroom lesson. Which reply is correct? (different from / different to than / similar from) Answer: different from — Different pairs with 'from' to show two things are not the same. 'Different to than' jams two prepositions together, and 'similar from' is the wrong meaning plus the wrong preposition.