Meeting girlfriends daughter - how do I make her like me?

My girlfriend and I are 23, she has a 5 year old daughter. I'm meeting her this weekend. My girlfriend and I are very serious and have been for a while, she's just very responsible about her daughter and who she lets into her life as her father isn't around. I know I'll be apart of her life for a long time and really really want to be someone she LOVES being around, looks up to, looks at like a friend, and trusts me and genuinely is happy I'm around. How can I make a good impression and make sure all goes well. I'm really nervous she won't like me and will turn off any attention to me. I don't want to be "moms boyfriend", but I don't Nessicarily expect her to ever call me dad. I just want to be cool, down to earth, connect with her and make sure she loves being around me. Our plan is to go out for breakfast Sunday morning and go from there. On a side note I'm a bodybuilder with a big stature, I'm a little nervous this could be off setting to her but on the other hand I think it might be funny/interesting to her. Do you think I should try to hide my physique as much as possible? via /r/Parenting http://ift.tt/2vpyJzv