The path of peace
If I were to offer any advice on taking steps for self-defence, know that there are few wrong paths. There is no 'best' as the fundamentals of striking, blocking and movement will serve you well regardless of style or system. Also know that it is a long road and your proficiency is a product of your input and perseverance.
Awareness and being mindful of your surroundings is first and foremost. Avoid, minimise, de-escalate and disengage where possible. There is no problem if you do not let a situation become one.
Once an engagement presents itself, seek to solve the problem quickly with purpose and aggression. Know that an opponent is rarely alone. Know that anything can be a weapon (or a shield). Know that you will be hit. You have one goal – survive.
Take up boxing for the cardio, fast hands and combos. The fitness itself is worth the price of admission. So is being comfortable in-close and taking strikes. Train so that delivering a combinations becomes second nature.
Take up a traditional martial art for the discipline, the culture and efficiency of movement. Respect the history and find the path of peace – know that this is real. Train so that your movement and strikes do not give away your intention.
Take up kick-boxing for the aggression, expression of power and the additional toolset of knees, elbows and clinches. Explore what it is like to explode with rawness and primal intent – feel its effect and consequence and from it, learn control. Train so that you can be effective at all ranges.
Take up wrestling or jujitsu for the groundwork, control and submission. Know that prolonged engagements rarely remain standing. Be comfortable with restriction. Be comfortable being close. Embrace the struggle. Train so that you have options regardless of your position.
Take up Krav Maga for the reality of combat and self-defence solutions. Know that life is not fair and gentlemen's rules do not exist. Be comfortable fighting dirty and take every advantage. Prepare for the worst and know that there will be more. Train so that you place your survival above all else.
Beyond this, there are three other skillsets that will serve you well. Take up parkour for effective pathfinding. Take up gymnastics for flexibility, power and body control. Learn physiology for knowledge of vital areas and anatomical limitations.
I have varying levels of expertise in each of these areas and the advice is merely a reflection of my journey and experience. For some, true success is defined as a lifetime of training without encountering an incident. For others, "it is better to a warrior in a garden than a gardener in a war." For myself, it is the confidence that allows me to walk in peace.