Now that you have checked in and have your boarding passes, you won't need your e-tickets. I'd print them and take them with as proof of purchase etc, but you won't need them.
When you arrive at the 'departures' area of the airport, look for the banks of tv screens which show all the flights which are departing in the next few hours. Find your flight on the screen (it will be referenced by flight number and destination as well as time of departure). That will then tell you which check in desk to go to. As you have already checked in, you will probably just be heading for the 'bag drop' queue, where you will stand in line with your cases. At the desk, the staff member will check your boarding cards and passports, then weigh your cases, label them and hand your documents back. Your cases are then gone until you land.
You will then be told which 'gate' to head for. Follow signs for departure gates. You will at this point come to a further check of boarding cards, as only passengers are allowed beyond that point. When someone has checked that, you will follow the directions (no where else to go!) and end up in a line for security. You have to place your hand luggage on the conveyor belt so that it can be scanned for bombs / liquids etc. At this stage you will be asked to remove any jackets or cardigans / loose clothing as well as belts and sometimes shoes. All go in a tray on the conveyor belt to be passed through a scanning machine.
You will then yourself walk through a person scanner. If you 'beep' you will be given a brief pat down to check you're not carrying anything. If not, you just walk through to the other side and collect your hand luggage from the conveyor belt. REMEMBER - you are not allowed to carry any liquids, including water or other drinks - in your hand luggage if the container of the liquid is over 100ml. Anything you do have (such as a small bottle of perfume, or deodorant) you have to put in a clear plastic bag. They have these at the security part for you to use.
When you've cleared security, you then walk through in to the departure areas, where you'll find duty free shopping, bars, sandwich shops etc. You can browse here or get food etc. You will see other banks of screens. These will have your flight on, and when the flight is maybe 45 minutes from departure, the screen will say "go to gate" and will list the departure gate for your flight. You then follow the signs to the departure gate where there are normally seats etc and wait until the flight is called, meaning they announce it is ready to board. Often they board flights by seat row, so they may say "would all passengers in rows 10-26 please board now". As you approach the gate to board, your passport and boarding cards are normally checked again.
Finally, you walk through onto the plane, find your seat and sit down!
At the other end, when you get off the plane, follow signs for baggage reclaim, check the screens to see which belt your bag will be on, wait for it to come round, take it off and head for the exit.
If you are on a package holiday with Thomson, you should look for people with clipboards from Thomson - these are reps and will tell you where to go next.
Good luck and have a great holiday!