You might get your tiles from the good DIY store but check local newspapers for a tile warehouse in your area – they'll have more on the display and can offer you a good discount. You should be able to take your adhesive, grout, and tools from the same retailer.
You need a shovel 6mm to 10mm for the wall and floor. 4mm for mosaics. You need an adhesive ready for the wall or ask for the best fast mixture for your floor. You need two empty buckets, a large sponge, grout/squeegee buoys, paddles for mixing powder, tape measure, spirit levels, cheap tile cutters: a diamond wet cutter and maybe a scraper.
Check how much this will cost and seriously consider whether it is worth buying: However a professional Perth tiler will only charge a few hundred for an average bathroom or kitchen and then you will not have a tool that roams afterward. Thus it is quite clear that you should reconsider your option of not having professional assistance on one hand.
Though, continuing with your DIY project, the important thing is to measure carefully, use your spirit level to get horizontal lines, set your pattern first and order far more tiles than you think you need! I start on a line that rests on and around the edge of the tub or from a focal point such as under the stove lid or around the window in the kitchen.
For the floor, check to see a pattern that will allow you the most complete tiles. Consider preparing dilute PVA on the wet surface area. It is worth looking around commercial tiles and your friend's house first to see what you like and dislike. Where are the tiles cut? What stands out?
Set one line at a time and then build a wall or cross the floor back to the door. Spread the adhesive horizontally with a shovel and pull the pressure to save the excess. Place the tiles carefully but not too strong. Use lighters to place your tiles. Try brick designs to save the hassle of aligning joints!