Can I fence if I'm overweight or out of shape, or should I lose weight first?
Yes, you can fence at any size, and you do not need to lose weight before your first class. If you can stand for a while, walk comfortably and bend your knees, you can learn the stance and footwork like everyone else. Beginner classes come in short bursts with plenty of breaks, and nobody expects a newcomer to last a whole evening of bouting. Plenty of larger fencers train several nights a week and compete for years. Fencing clubs also tend to be welcoming places, partly because the sport is small and everyone remembers being new.
Skill carries much further than body shape in this sport. Hand speed, clean bladework, timing and distance (how far you stand from your opponent) win touches, and experienced fencers of every build beat younger, leaner opponents all the time. Being honest about the trade-offs: a larger body is a larger target, and quick footwork and endurance take more work to build. At the very top of competitive fencing, fitness clearly matters. But that is fitness, meaning strength, mobility and stamina, not a number on a scale, and it improves with training at any size.
The practical hurdles are gear and knees. Club loaner jackets often stop at average sizes, so call ahead and ask what they have. If nothing fits, several fencing manufacturers sell extended sizes or make jackets and knickers to measure; that costs more and takes longer, so start early. Lunging is also demanding on the knees and hips, and more so when you carry more weight. Build up gradually, add simple leg and hip strength work outside class, and take extra breaks between bouts. Sharp, lasting or swelling pain means seeing a doctor or physical therapist, not pushing through.
If you have a health condition or have been inactive for a long time, a quick check with your doctor before starting is sensible. And if you have ever struggled with disordered eating, keep your fencing goals about skills and stamina rather than weight; comparing yourself to the leanest fencer in the room helps nobody's results. Tell your coach about any limits so they can adjust drills. Many people find that a sport they actually enjoy is the one they keep showing up for, and showing up is what builds fitness.