My tip for learning a new language is to use your interests.
So, for example, if you're interested in cooking, look up a recipe or a cooking video in that language of a dish you like.
And also as is mentioned above me, try to use the language as much as possible: find someone to write/talk with, watch the news in that language and maybe change the language of your phone to the language you want to learn.
In case of Spanish, try to not be so hard with yourself to be perfect in the language. Us as Spanish native speaker we get weird with the words and the majority of the time we have to google what is the most appropriate way to say something. We’re constantly learning!
If you want to learn a new language, you have to be consistent and also look that you meet native speakers who would like to practice the language of your interest with you on a regular basis. Also, I recommend using some language learning app if you are an absolute beginner in the language(s) you would like to learn.
It is. of course. most helpfull to travel and stay for a while in a country where the language is spoken. If that is not possible i found it very helpfull to watch movies in that language and read books. Listen to musik is also helpfull.
I think that everyone has to find his/her own way of learning a foreign language. Regularity is the key. Keep in touch with the language on a regular basis so that it becomes a common thing for you. To learn vocabulary it helps to decorate your home with notes so that you can look at them everytime you pass by. It also helps if you write your shopping list in the foreign language. A great plus is if you have contact with native speakers so that you can practice the language actively.
You can practice and learn by doing small things too! for example, changing the language in your phone or language preferences in social media so you can get content in it and get accustomed to it.
I used to do this and it helped me a lot.
Use different platforms, youtube (for entertainment), duolingo (vocab + refresh yourself), books, also universities may have free online lessons you can read through that teach grammar
Try to immerse yourself with the target language as much and as often as possible. It is also good to have a penpal to chat on a regular basis. There are also several apps that I would recommend: LingQ, Italki, Babbel, Mondly, anki.