asking about ranked games

so, hi. this season was my first time playing ranked games, so i was unranked. i won 4 and lost 6 solo/duo matches and got into Silver IV. i want to know more about the system of how things go for ranked games, what is LP, what are Promos, and what does ELO stand for, ( i know noob questions, but it's my first time playing ranked cause i was so scared of getting flamed since i'm a main support. )and if i win more ranked matches do i get into a higher ranked or do i stay in silver IV till the next season. sorry if these are stupid questions to ask but help c: