Yeah, no trainers there. You're basically on your own
You can do most of the major lifts with dumbbells, though you may need to adjust the technique.
Bench Press - actually harder with dumbbells since you don't have a central axle to stabilize yourself on.
Deadlifts - The range of motion and action has to change due to the size of the dumbbells and their physical difference from barbells. More specifically, you likely won't be picking them up from the ground. Look up how to do Romanian deadlifts for a variation that works a bit better on the dumbbells
Squats - You can hold them on your shoulders and do front squats if they're light, but as the weight increases you'll likely have to do the regular variant and hold them at your sides. Having started with this and switched to barbell squats, the two can barely be compared; holding a barbell on your shoulders drastically changes the muscles you activate. However, you make do with what you have.
Overhead Press - This is pretty straight forward, works similar in scope to the bench press
Look at the starting strength exercises and make what adjustments necessary; replace power cleans with overhead presses unless you can find someone to suggest a decent dumbbell alternative. Make what small adjustment you deem fit for your own schedule.
I got into a serious workout schedule the same way, with dumbbells only except in a company gym. It's not ideal, but you're not crippled by any means and can make some decent advancements, at least enough to pull yourself out of the "skinny-fat" hole and make you stronger than most of the average people out there. Come here or find other workout forums where you feel comfortable for support; you can't hope to exceed by looking to average people for approval.