Good luck…it’s a great experience! I had a sports massage every month in last 7 months or so to iron out any niggles, which was well worth it, and if you book a block, you often get a discount. Practice eating whilst training, and something palatable. My ham sandwiches on the bike were the envy of other competitions forcing down a gel; if you eat something every half hour after the swim you will be ok. I put some interesting races into the build up as good motivation in their own right. Hilly half marathon on exmoor and the Old Man of Coniston Tri we’re brutal courses that made a groomed ironman course, even a ‘hilly’ one feel much more do-able. Training plan is key…there are lots out there. Worth accepting that you will probably lose about 10% of sessions due to illness/ work etc and that is ok!