The first language you learn, your mother tongue, usually comes with little conscious effort. If you're lucky, you might even acquire more than one language in the so-called 'critical period' of language learning, believed to end sometime between ages 4-12. After that, it doesn’t come so easy, as you might have found out at school.
Something that might help is finding out about your learning style: are you a visual, auditory or kinaesthetic learner?
The visual learner might benefit from writing down words and phrases over and over again.
The auditory learner could gain from reading out loud or recording their own vocabulary lists and listen back to them.
The kinaesthetic learner may enjoy learning in a group or using flash cards or anything else that satisfies their hunger for 'experience'.
Finding what works for you could speed up your language acquisition - or at least make it more enjoyable!