Teach sit by raising a treat over her head. Most dogs will automatically sit and look up. As her bum is moving to the floor say “sit” and as her bum hits the floor, mark and reward. To mark you can use a clicker or say “good” and rewards with a small treat. Don’t force her bum on the floor, this is not good for little joints.
To teach a strong “come” or recall, it is important that you make yourself the most exciting thing to your dog at the time. I practise this with my clients by getting them to run around the room like crazy people and encourage their dogs to chase them, making a game of it. The important thing is, once she has come to you whether it is on your command or voluntary, you mark and reward. In the early stages, encourage your puppy to come to you as often as possible, even if you are just sat on the sofa. Keep a supply of treats on you at all times so that when you call your puppy and she comes trotting over you can reward her. To avoid the puppy associating the recall command with negative feelings, try not to always put her on a lead or in the car which will signal the end of fun time. Instead practise this when you are able to reward the behaviour (recall) and then allow her to continue having fun off the lead. This wil teach her that, just because you have called her into you, it doesn’t necessarily mean that her fun is going to stop.
At this stage I recommend that she can sit, stay and come on command. “Come” and “Stay” in particular could save her life. For example, if you open the car door and she bolts out without permission she could get hit by another car. If she knows that when you say “stay” she doesn’t move, this will prevent an accident.
With toilet training, you can’t expect her to go out automatically just because you leave the door open for her. She needs to learn from you where it is acceptable for her to go. Every hour or so (especially after she has eaten, drank or just woken up) take her out. When she goes to the toilet, reward the behaviour. You can even introduce a key word (like toilet) to encourage her to go where you are happy for her to go.
I strongly recommend puppy classes though. These will not only teach your puppy basic obedience but it will help her to socialise with other dogs and people.