The best course of action is to talk to a trainer and coach. A coach will outline what swimming and bike workouts you need to do...the trainer can help you out with the weights and weight loss. Some coaches know about weigths, but most do not which is why i recommend talking to two separate people. Make sure the trainer is someone knowledgeable about sport, because training for endurance is different than doing weights for general health.

the coach might be a bit more of a long term investment, but there are many online coaches with generic programs out there that are not so much money. the trainer you can meet up with once a month.

you can invest in weights and bands and a ball and do your workouts at home, but it depends on your personality and motivation. I have actually been researching (i am a trainer - my specialty is in-home training) and at home exercisers tend to stay at it for much longer as long as they have instruction. pretty interesting.

Good luck!

hannah