body lotion/cream can apply anytime although stretch marks - they are in the genes. you either get them or you dont't. not very much you can do about them, unfortunately.
antenatal class can start in 2nd tri
confinement lady - i DIYed with a bit of help from my mom for the first baby so can't advise on that. but i suppose no harm booking early
meantime, first tri is when you should get a lot of rest!