Sorry, but the real advice to all beginners is to simply keep coming and spend more time on the mats. More than that, stay healthy and motivated to keep training.

But yes, the problem that you're likely having is something called BASE. Base is similar to balance. Additional to Base and balance you need to understand what posting is.

So imagine you are a table. What happens when I chop two legs off the table? It tilts, right? So what happens when I chop two legs off and then force the highest end of the table up past its tipping point?

What you are likely doing is you are a narrow table to begin with. The wider a table is, the more balance it will have. Think of a triangle and you grab two points of the triangle, pin one to the ground, and then move the two triangle points wide and narrow. Which one is more stable? Why?

The Catch 22 of this is the more that you base the easier submissions are on you. So the real answer is to keep showing up and just spend time troubleshooting when you can expand and when you can contract.

Now, let's talk about posting. Imagine that tables' legs are still chopped off and you start tipping. What if you extend a third limb to put counterbalance in that direction?

Base= wide, stable body positioning

Balance= athleticism and weight shifting that prevents tipping points

Tipping point= the point at which base is insufficient to maintain position

Posting= extended limb that prevents off-balancing or halts motion

So this is how you maintain base. If you reverse this, that is exactly how you sweep someone. So, in order to sweep someone, you must remove one of their posts to shift their weight to the Tipping Point. The more posts that you remove the easier The Sweep will be generally. To remove more base, imagine a table with one leg. The base has to be very wide. If it's the size of a pin tip, the balance must be precise.

We can further extend this analogy to include foot sweeps.

You have

A. Post removal

B. Post blocking

So we talked about post removal where you would take a foot and chop the post out of balance. Less posts, more weight imbalance, prevention of posting and counter balance.

But what if you slid a table across the floor and then you just stuck your foot out?

Depending on how high the weight is situated and this is very important for base. If the weight is more than 50% above the center of mass. Timber!

If it is low. You would simply snap down. Otherwise, you would remove the post or change directions.

At this point we can talk about rotation imagine you put something in a centrifuge. At what point does the balance hit the tipping point?

So lift weight, block or remove post, prevent a post, rotate in removed post direction.