welcome to TAI brother

May Allaah bless you and give you a lot of knowledge.
As for your topic, as well as zina being haraam, the "foreplay" of zina is also haraam.
So things that can lead to zina also must be avoided - because as you already know, the devil is always there to whisper to the person and encourage him to sin - and the best way to avoid the evil of the devil is to stay well away from anything to do with something haraam.
For example, being alone with a member of the opposite gender who is not your mum, grandma, etc. is haraam - the devil might try to encourage them to do more things that are haraam.
Also, for men to look at the faces and hands of marriageable women with desire and at other parts of their bodies with or without desire is haraam. And I can tell you that this is a big source of evil these days.
Also, to think dirty or talk dirty - that is haraam.
Also something that many people have unfortunately forgotten about:
To intentionally touch the marriageable woman without a barrier or to touch her lustfully with a barrier is haraam.
Overall, just avoid these risky situations - this life is just decades but the next life Allaah made it everlasting.
Allaah will reward you according to your patience and effort in avoiding all what He ordered you to avoid.
And as for marriage relationships - rely on God and be aware that starting a relationship on the wrong foot is not something good.
All of us want to be blessed by Allaah in our marriages and so it is wise to go about getting a spouse the 100% halaal way.
Rely on God the true reliance & He will give you.
May Allaah protect us from the sins and grant us pious spouses to help us raise pious children who will make du3aa' for us in our lifetime and after our death.
aameen Allaahumma aameen.