do/ play sports and others please help me.

is it right when I write: in order to put on the weight you should do more exercises, eat less junk food, do more riding bike, do more walking and do more sports.

I very much doubt that ‘put on weight’ is your intended meaning looking at the advice given.

In order to lose weight you should eat less junk food and do more exercise, such as participating in sports and taking part in activities such as bike riding or walking.

In order to put on weight you should combine a carbohydrate-rich diet with exercises designed to develop muscle strength, such as exercises using weights.

MAy I say " do more riding bike, do more walking and do more sports" I always see play sports not do sports. Please help me

Although you can use ‘do’ with terms like ‘do more walking’ and ‘do more sports’,
these are far more elegantly expressed than the alternatives with ‘do’,
Take more exercise, take walks, play sports…

‘Do more bike riding’ sounds odd because you don’t need’do’ there at all. You could just say ‘ride your/a bike more often’