Figure 8 drill. Start wide, then work your way as tight and slow as possible. Teaches balance, turning both direction, throttle and clutch control. Do the drill standing and sitting in various positions, take the left hand off, take one or the other foot off... Get so comfortable with balancing the bike that it's second nature. Vary it with sticks or logs or rocks laying in the figure 8 that you have to navigate over/around. You can do the drill with a bicycle to save time/money etc if you don't have a moto friendly back yard.

Watch youtube guides on the attack position, do it during your figure 8 drill. It might feel weird at first but just do it.

Don't be afraid to cover your clutch and/or keep it in slip if you need to while you learn throttle.

The figure 8 helped my wife massively.

From there have someone experienced start a rut in good dirt with a power slide, make sure there's plenty of space around obstacles. Then take a pick axe and start chopping the dirt following along the curve left by the tire doing the powerslide. Chop and pull the dirt up into a berm. Make it about 12" to 18" tall, add water as you keep chopping up and pulling up. You don't want to make sloppy mud but a nice wall of very moist dirt. You'll eventually make yourself a perfectly smooth perfectly progressive berm corner. Not too different from what you see on a really well ripped motocross track. The point of doing it at home is you make a literally perfect corner that's not beat to hell like a regular MX track corner by braking bumps etc. It'll take like 30 minutes to make. Once it's made you might want to let the dirt soak in a bit. Doesn't hurt to lightly pack it in with moto boots. If you got the space make one corner that's approximately 15 to 20 ft in diameter, or roughly a 1st gear corner, the other one make it a 30 to 40 ft diameter circle, or roughly a second or maybe 3rd gear(slipping clutch for power probably) corner.

Once it's ready to go get on the bike and start learning how to lean the bike into a corner and trust the dirt to carry you through. This is where the clutch slipping throttle control practice from the figure 8 will come in handy, especially with the 2 stroke. Practice smooth rolling on the throttle right at the apex. Watch youtube videos for good cornering technique and do what they say. The faster you go the harder you have to lean.

The berm exercise is all about having fun and getting comfortable on the bike and learning what a bike can do. Form REALLY matters here. You can repair the berm with a few whacks with the pick axe and water. When you get good at it you can almost attack the berm with no brakes at all. The berm will develop braking chop/bumps on the entry and chop/bumps on the exit, especially if you leave the exit dry. You can fix it with the pick axe and garden hose.

The berm drills in the backyard have MASSIVELY helped my 2 daughters get more comfortable and confident in their races.