1st tone is a level tone, it does not change pitch.
2nd tone is a rising tone, you voice starts low and goes up in pitch as you say the word.
3rd tone is a falling then rising tone. Your pitch starts in the middle, falls a little than rises above your original pitch.
4th tone is a falling tone, you voice goes from a high pitch to a low pitch as you say the word.
Some tricks I know for helping with tones are
Hold your finger in front of you and draw the tones with your finger as you say the words.
For 1st tone just be careful not to change the pitch of your voice, imagine you are balancing a glass, if your tone moves even a bit, the glass will fall.
For 2nd tone, try raising your eyebrows as you say the word.
For 3rd tone, try swinging your head down then up in a circular motion, or imagine you are sitting down then standing up again.
For 4th tone, try stamping your foot, it sounds a little angry 4th tone I think or imagine a pencil sliding down a ruler, it must go all the way from top to bottom!
Tones are the hardest part of Chinese, I have been learning 3 years and still struggle, try not to worry too much, you'll be amazed what Chinese people can understand! Just keep practising lots, that's the best advice I can give you.