how do you start the first lesson in french... ?
I did this, but I'm sent to whatever my last lesson was (in this case lesson 3). I have a terrible memory, and I'd like to redo Lesson 1 from the beginning, but the "redo lessons" buttons on the right will start from the evaluation instead of giving me the actual lesson.
Needless to say, I get most of it wrong, cause I can't remember what the words mean.
I'm not sure what you mean when you say "evaluation instead of giving me the actual lesson". The lessons are all technically evaluations. You learn as you go, earn skill points, and level up. If you're having trouble remembering what words you've seen, I suggest you look over your vocabulary [ http://duolingo.com/#/vocab ].
To redo your previous lessons go to your Skill Tree and click any of the previous lessons you have completed. Then it will direct you different page where there will be an image of a blue book. Click it and start learning again.
If you have trouble, scroll your cursor over the words you do not know and it will give you a peak at what they mean. Even though you keep getting it wrong, soon enough you will start to remember them. Keep trying! Good luck.