All I have is a pair of marching sticks and a cheap pad, what are some exercises that can help with coordination and muscle required for marching tenors.
Many DCI corps have publicly available warm up books (e.g. Oregon Crusaders' Quads Pack). Many of these exercises are easier than you'd expect for DCI, and focus on the fundamentals of technique - you can play these at whatever tempo you feel comfortable, ensuring technique is good, and then build up the speed.
Rudiments are key to almost everything you will do. Try to voice some rudiments around all the different drums, then when you feel comfortable try playing through them all whilst watching TV, so that you can spend 30 mins or so on the same thing without getting too bored. This will help with the muscle memory aspect.