I sprinkle baking soda in the oven and spray with vinegar diluted 1:1 with water. Scrub and let sit. Then scrub some more (spray again if it's dry) and wipe clean.
You can get an over cleaner. Now they have a cold one that you do not have to heat your oven. Works great. You can take your oven racks outside & put on newspaper or what you have. Spray both sides. Follow instructions on can. I rinse them outside & them wash them in the sink & then dry them. Wipe out your oven until it is clean. I then spray it with glass cleaner & wipe it with paper towels until it completely clean. I use a lot of paper towels. You can use old wash rags or what you like to clean with. I have a stove is self cleaning now. I still wipe it out real good.
Hello -these Hometalk links should be helpful.
12 Easy Ways To Make Sure Your Oven Is Always Spotless | Hometalk
Is it self cleaning?
I use Easy Off oven cleaner.
If it is not self cleaning then try the Oven Easy Off which has no fumes since it goes on cold. Works great. Remove the racks, place on newspapers outside and spray, let sit, maybe scrub if you have to, and then hose off.
HG spray is working very good: https://amzn.to/2FGTMQl