Riding Horse Back

I've Decided To Begin Horse Back Riding Again After My Fourteenth Birthday (In A Month), And I Haven't Ridden Since The Fourth Grade. I Remember That I Had Riding Pants, A Helmet, Boots And A Crop, But Those Don't Fit Anymore. Are Those All The Things I Need To Repurchase? Are There Any Discount Stores For Beginners? Thanks :D And Any Tips For Riding Horses?